cp's OEIS Frontend

A154931 Third column of A154921.

%I A154931 #17 Feb 03 2019 08:25:33
%S A154931 1,3,18,130,1125,11361,131124,1702548,24562575,389799355,6748339158,
%T A154931 126565340694,2556332651145,55320126580005,1276961156453160,
%U A154931 31318513972988008,813295166343147315,22293401161982239071,643251586018800611370,19488333337058966337930
%N A154931 Third column of A154921.
%H A154931 Alois P. Heinz, <a href="/A154931/b154931.txt">Table of n, a(n) for n = 2..424</a>
%F A154931 E.g.f.: 1/2!*x^2/(2-exp(x)) = x^2/2! + 3*x^3/3! + 18*x^4/4! + .... - _Peter Bala_, Apr 20 2012
%p A154931 b:= proc(n, p) option remember; `if`(n=0, p!,
%p A154931       add(b(n-j, p+j)/j!, j=1..n))
%p A154931     end:
%p A154931 a:= n-> b(n-2, 2)/2:
%p A154931 seq(a(n), n=2..23);  # _Alois P. Heinz_, Feb 03 2019
%t A154931 With[{nn=20},Drop[CoefficientList[Series[(x^2/2)/(2-Exp[x]),{x,0,nn}],x] Range[0,nn]!,2]] (* _Harvey P. Dale_, Jan 16 2013 *)
%Y A154931 Cf. A154921.
%K A154931 nonn,easy
%O A154931 2,2
%A A154931 _Mats Granvik_, Jan 17 2009
%E A154931 a(9) through a(18) from _Peter Bala_, Apr 20 2012
%E A154931 a(19)-a(21) from _Alois P. Heinz_, Feb 03 2019