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 A308463 #9 May 29 2019 03:30:06
%S A308463 1,1,4,7,51,16,876,2045,15475,15256,678569,2006863,27644436,46065293,
%T A308463 669225640,5235101739,82864869803,234937438645,5832742205056,
%U A308463 25117329128165,235703526149476,1886712616836675,44152005855084345,102153081219673712,3428690854204959151
%N A308463 a(n) = Sum_{k=1..n, gcd(n,k) = 1} Stirling2(n,k).
%t A308463 a[n_] := Sum[If[GCD[n, k] == 1, StirlingS2[n, k] , 0], {k, 1, n}]; Table[a[n], {n, 1, 25}]
%o A308463 (PARI) a(n) = sum(k=1, n, if (gcd(n,k)==1, stirling(n, k, 2))); \\ _Michel Marcus_, May 28 2019
%Y A308463 Cf. A000110, A008277, A056188, A096314, A308037.
%K A308463 nonn
%O A308463 1,3
%A A308463 _Ilya Gutkovskiy_, May 28 2019