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 A309014 #9 Jul 06 2019 13:47:25
%S A309014 1,1,0,1,1,2,1,1,2,3,1,2,3,3,2,1,3,4,1,3,4,5,3,2,5,5,2,3,5,4,3,1,4,5,
%T A309014 1,4,5,7,4,3,7,8,3,5,8,7,5,2,7,7,2,5,7,8,5,3,8,7,3,4,7,5,4,1,5,6,1,5,
%U A309014 6,9,5,4,9,11,4,7,11,10,7,3,10,11,3,8,11,13,8,5,13,12,5
%N A309014 a(n) = Sum_{k=0..n} (-1)^(n-k) * (Stirling2(n,k) mod 2).
%F A309014 G.f.: 1 + x * (1 + x^3) * Product_{k>=1} (1 + x^(2^k) + x^(2^(k+1))).
%F A309014 a(0) = 1; a(2*k+1) = A002487(k+1); a(2*k+2) = A002487(k).
%t A309014 Table[Sum[(-1)^(n - k) Mod[StirlingS2[n, k], 2], {k, 0, n}], {n, 0, 90}]
%t A309014 nmax = 90; CoefficientList[Series[1 + x (1 + x^3) Product[(1 + x^(2^k) + x^(2^(k + 1))), {k, 1, Floor[Log[2, nmax]] + 1}], {x, 0, nmax}], x]
%o A309014 (PARI) a(n) = sum(k=0, n, (-1)^(n-k) * (stirling(n,k,2) % 2)); \\ _Michel Marcus_, Jul 06 2019
%Y A309014 Cf. A001316, A002487, A007306, A008277, A048993, A060632, A070990.
%K A309014 nonn
%O A309014 0,6
%A A309014 _Ilya Gutkovskiy_, Jul 06 2019