This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A358495 #11 Nov 19 2022 15:00:19
%S A358495 1,2,1,2,17,506,48772,13681602,12287555282,33669343492094,
%T A358495 311704008906073448,9309805333008203501246,
%U A358495 987309241535765332024955809,351345748109942610415182510895442,459648902729700156671704473390158212154,2067884865276847662816755891452805155809167114
%N A358495 a(n) = Sum_{k=0..n} binomial(binomial(n, k), n).
%F A358495 a(n) ~ c * binomial(binomial(n, n/2), n), where c = EllipticTheta[3,0,1/E^2] = JacobiTheta3(0,exp(-2)) = A218792 = 1.271341522189... if n is even and c = EllipticTheta[2,0,1/E^2] = JacobiTheta2(0,exp(-2)) = 1.23528676585389... if n is odd.
%F A358495 Equivalently, a(n) ~ c * 2^(n^2 + n/2 - 1/2) * exp(n - 1/4) / (Pi^((n+1)/2) * n^((3*n+1)/2)).
%t A358495 Table[Sum[Binomial[Binomial[n, k], n], {k, 0, n}], {n, 0, 16}]
%o A358495 (PARI) a(n) = sum(k=0, n, binomial(binomial(n, k), n)); \\ _Michel Marcus_, Nov 19 2022
%Y A358495 Cf. A357871, A358496.
%K A358495 nonn
%O A358495 0,2
%A A358495 _Vaclav Kotesovec_, Nov 19 2022