cp's OEIS Frontend

A024428 S(n,n) + S(n-1,n-2) + S(n-2,n-4) + ... + S(n-k+1,n-2k+2), where k = [ (n+1)/2 ] and S(i,j) are Stirling numbers of second kind.

%I A024428 #13 Jul 11 2019 01:51:00
%S A024428 1,1,2,4,8,18,42,102,260,684,1860,5216,15020,44388,134336,415672,
%T A024428 1313696,4234904,13911528,46525992,158279872,547327904,1922455440,
%U A024428 6854491840,24794405328,90940138256,338037825952,1272862982272,4853075024192
%N A024428 S(n,n) + S(n-1,n-2) + S(n-2,n-4) + ... + S(n-k+1,n-2k+2), where k = [ (n+1)/2 ] and S(i,j) are Stirling numbers of second kind.
%F A024428 G.f.: Sum_{k>=0} x^k / Product_{l=1..k} (1-l*x^2). - _Ralf Stephan_, Apr 18 2004
%F A024428 G.f.: 1/x/Q(0) - 1/x where Q(k)= 1 - x/(1 - x^2*(k+1)/Q(k+1)); (continued fraction). - _Sergei N. Gladkovskii_, Apr 14 2013
%K A024428 nonn
%O A024428 1,3
%A A024428 _Clark Kimberling_
%E A024428 More terms from _Sean A. Irvine_, Jul 10 2019