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 A351146 #18 Dec 10 2023 09:31:13
%S A351146 1,6,29,131,572,2448,10341,43288,180003,744712,3068793,12605411,
%T A351146 51642528,211110240,861409918,3509341245,14277424978,58017460260,
%U A351146 235512889296,955146370152,3870511127394,15672817355658,63421721139479,256488917828150,1036722699748068,4188329011110360
%N A351146 a(n) = Sum_{k=1..n} binomial(2*n,n+k)*A000005(k).
%D A351146 D. E. Knuth, The Art of Computer Programming Second Edition. Vol. 3, Sorting and Searching. Chapter 5.2.2 Sorting by Exchanging, pages 138 (exercise 52), 637 (answer to exercise). Addison-Wesley, Reading, MA, 1998.
%H A351146 Vaclav Kotesovec, <a href="/A351146/b351146.txt">Table of n, a(n) for n = 1..1650</a>
%F A351146 a(n) = A351145(n,n).
%F A351146 a(n) ~ 4^(n-1) * (log(n/4) + 3*gamma + 1/sqrt(Pi*n)) [Knuth, 1998]. - _Vaclav Kotesovec_, Aug 04 2022
%t A351146 Table[Sum[Binomial[2*n, n + k] * DivisorSigma[0, k], {k, 1, n}], {n,1,20}] (* _Vaclav Kotesovec_, Aug 04 2022 *)
%o A351146 (PARI) a(n) = sum(k=1, n, binomial(2*n, n+k)*numdiv(k)); \\ _Michel Marcus_, Feb 02 2022
%Y A351146 Diagonal of A351145.
%Y A351146 Cf. A000005, A356338, A356339, A356340.
%K A351146 nonn
%O A351146 1,2
%A A351146 _Hugo Pfoertner_, Feb 02 2022