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 A357901 #11 Oct 19 2022 13:40:45
%S A357901 1,0,0,1,1,2,7,27,131,771,5320,42119,376174,3740018,40956593,
%T A357901 489749100,6348744124,88677555115,1327628770657,21208195526882,
%U A357901 360053293342379,6473501562355779,122874692176838047,2455382300127368557,51524333987938459606,1132787775301639812263
%N A357901 a(n) = Sum_{k=0..floor(n/3)} |Stirling1(n - 2*k,k)|.
%F A357901 G.f.: Sum_{k>=0} x^k * Product_{j=0..k-1} (j + x^2).
%o A357901 (PARI) a(n) = sum(k=0, n\3, abs(stirling(n-2*k, k, 1)));
%o A357901 (PARI) my(N=30, x='x+O('x^N)); Vec(sum(k=0, N, x^k*prod(j=0, k-1, j+x^2)))
%Y A357901 Cf. A000142, A343579, A357902.
%K A357901 nonn
%O A357901 0,6
%A A357901 _Seiichi Manyama_, Oct 19 2022