Srinivasa Ramanujan is an Indian mathematician who is famously known for solving math problems with sudden and inexplicable flashes of insight. From his Wikipedia page:
Imagine that you are on a street with houses marked 1 through n. There is a house in between (x) such that the sum of the house numbers to the left of it equals the sum of the house numbers to its right. If n is between 50 and 500, what are n and x?' This is a bivariate problem with multiple solutions. Ramanujan thought about it and gave the answer with a twist: He gave a continued fraction. The unusual part was that it was the solution to the whole class of problems. Mahalanobis was astounded and asked how he did it. 'It is simple. The minute I heard the problem, I knew that the answer was a continued fraction. Which continued fraction, I asked myself. Then the answer came to my mind', Ramanujan replied."[60][61]
and
... Ramanujan's first Indian biographers describe him as a rigorously orthodox Hindu. He credited his acumen to his family goddess, Namagiri Thayar (Goddess Mahalakshmi) of Namakkal. He looked to her for inspiration in his work[12]:36 and said he dreamed of blood drops that symbolised her consort, Narasimha. Afterward he would receive visions of scrolls of complex mathematical content unfolding before his eyes.[12]:281 He often said, "An equation for me has no meaning unless it represents a thought of God."[58]
His style of mathematical reasoning was completely novel to the mathematicians around him, and led to groundbreaking research:
During his short life, Ramanujan independently compiled nearly 3,900 results (mostly identities and equations).[4] Many were completely novel; his original and highly unconventional results, such as the Ramanujan prime, the Ramanujan theta function, partition formulae and mock theta functions, have opened entire new areas of work and inspired a vast amount of further research.[5] Nearly all his claims have now been proven correct.[6] The Ramanujan Journal, a peer-reviewed scientific journal, was established to publish work in all areas of mathematics influenced by Ramanujan,[7]and his notebooks—containing summaries of his published and unpublished results—have been analyzed and studied for decades since his death as a source of new mathematical ideas. As late as 2011 and again in 2012, researchers continued to discover that mere comments in his writings about "simple properties" and "similar outputs" for certain findings were themselves profound and subtle number theory results that remained unsuspected until nearly a century after his death.[8][9] He became one of the youngest Fellows of the Royal Society and only the second Indian member, and the first Indian to be elected a Fellow of Trinity College, Cambridge. Of his original letters, Hardy stated that a single look was enough to show they could only have been written by a mathematician of the highest calibre, comparing Ramanujan to other mathematical geniuses such as Euler and Jacobi.
If HCH is ascription universal, then it should be able to epistemically dominate an AI theorem-prover that reasons similarly to how Ramanujan reasoned. But I don't currently have any intuitions as to why explicit verbal breakdowns of reasoning should be able to replicate the intuitions that generated Ramanujan's results (or any style of reasoning employed by any mathematician since Ramanujan, for that matter).
I do think explicit verbal breakdowns of reasoning are adequate for verifying the validity of Ramanujan's results. At the very least, mathematicians since Ramanujan have been able to verify a majority of his claims.
But, as far as I'm aware, there has not been a single mathematician with Ramanujan's style of reasoning since Ramanujan himself. This makes me skeptical that explicit verbal breakdowns of reasoning would be able to replicate the intuitions that generated Ramanujan's results, which I understand (perhaps erroneously) to be a necessary prerequisite for HCH to be ascription universal.
I think the "sudden and inexplicable flashes of insight" description of Ramanujan is exaggerated/misleading.
On the first example of the post: It's not hard to see that the problem is, by the formula for triangular numbers, roughly(!) about the solvability of
x(x+1)2=n(n+1)4.
Since t(t+1) is roughly a square - 4t(t+1)=(2t+1)2−1 - one can see that this reduces to something like Pell's equation a2−2b2=1. (And if you actually do the calculations while being careful about house x, you indeed reduce to a2−8b2=1.)
I think it's totally reasonable to expect an experienced mathematician to (at a high level) see the reduction to Pell's equation in 60 seconds, and from that making the (famous, standard) association to continued fractions takes 0.2 seconds, so the claim "The minute I heard the problem, I knew that the answer was a continued fraction" is entirely reasonable. Ramanujan surely could notice a Pell's equation in his sleep (literally!), and continued fractions are a major theme in his work. If you spend hundreds-if-not-thousands of hours on a particular domain of math, you start to see connections like this very quickly.
About "visions of scrolls of complex mathematical content unfolding before his eyes": Reading the relevant passage in The man who knew infinity, there is no claim there about this content being novel or correct or the source of Ramanujan's insights.
On the famous taxicab number 1729, Ramanujan apparently didn't come up with this on the spot, but had thought about this earlier (emphasis mine):
This is not say Ramanujan wasn't a brilliant mathematician - clearly he was! Rather, I'd say that one shouldn't picture Ramanujan's thought processes as wholly different from those of other brilliant mathematicians; if you can imitate modern Field's medalists, then you should be able to imitate Ramanujan.
I haven't read much about Ramanujan; these are what I picked up, after seeing the post yesterday, by thinking about the anecdotes and looking to the references a little.