# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a357902 Showing 1-1 of 1 %I A357902 #10 Oct 19 2022 13:40:39 %S A357902 1,0,0,0,1,1,2,6,25,123,731,5090,40595,364650,3641903,40026609, %T A357902 480029801,6237662582,87298953249,1309161984315,20942605407386, %U A357902 355971044728635,6406714801013007,121715861296354116,2434125806029297550,51113325326999860554,1124432395936987325868 %N A357902 a(n) = Sum_{k=0..floor(n/4)} |Stirling1(n - 3*k,k)|. %F A357902 G.f.: Sum_{k>=0} x^k * Product_{j=0..k-1} (j + x^3). %o A357902 (PARI) a(n) = sum(k=0, n\4, abs(stirling(n-3*k, k, 1))); %o A357902 (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 A357902 Cf. A000142, A343579, A357901. %K A357902 nonn %O A357902 0,7 %A A357902 _Seiichi Manyama_, Oct 19 2022 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE