%I #10 Oct 19 2022 13:40:39
%S 1,0,0,0,1,1,2,6,25,123,731,5090,40595,364650,3641903,40026609,
%T 480029801,6237662582,87298953249,1309161984315,20942605407386,
%U 355971044728635,6406714801013007,121715861296354116,2434125806029297550,51113325326999860554,1124432395936987325868
%N a(n) = Sum_{k=0..floor(n/4)} |Stirling1(n - 3*k,k)|.
%F G.f.: Sum_{k>=0} x^k * Product_{j=0..k-1} (j + x^3).
%o (PARI) a(n) = sum(k=0, n\4, abs(stirling(n-3*k, k, 1)));
%o (PARI) my(N=30, x='x+O('x^N)); Vec(sum(k=0, N, x^k*prod(j=0, k-1, j+x^3)))
%Y Cf. A000142, A343579, A357901.
%K nonn
%O 0,7
%A _Seiichi Manyama_, Oct 19 2022
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