A357922 - OEIS

%I #8 Oct 20 2022 12:44:53

%S 1,0,0,0,0,1,1,2,6,24,121,723,5051,40370,363154,3630565,39929874,

%T 479111219,6228047601,87188921464,1307794924973,20924276449014,

%U 355707232027825,6402657184129671,121649439722758345,2432972744390660437,51092165603897459951

%N a(n) = Sum_{k=0..floor(n/5)} |Stirling1(n - 4*k,k)|.

%F G.f.: Sum_{k>=0} x^k * Product_{j=0..k-1} (j + x^4).

%o (PARI) a(n) = sum(k=0, n\5, abs(stirling(n-4*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^4)))

%Y Cf. A000142, A343579, A357901, A357902.

%Y Cf. A357920.

%K nonn

%O 0,8

%A _Seiichi Manyama_, Oct 20 2022