A192568 - OEIS

%I #6 Mar 30 2012 18:55:30

%S 1,1,19,356,13626,712482,51437310,5021800835,618616762763,

%T 95445366568311,18045402520903033,4089264784742659744,

%U 1098689143687870325930,345713999063910185516303,125935810020098258689919235,52660666992259419412862687142

%N a(n) = sum(Stirling2(n,k)*Stirling2(n+1,k+1)*Stirling2(n+2,k+2),k=0..n).

%t Table[Sum[StirlingS2[n,k]StirlingS2[n+1,k+1]StirlingS2[n+2,k+2],{k,0,n}],{n,0,100}]

%o (Maxima) makelist(sum(stirling2(n,k)*stirling2(n+1,k+1)*stirling2(n+2,k+2),k,0,n),n,0,24);

%Y Cf. A008275, A008277.

%K nonn

%O 0,3

%A _Emanuele Munarini_, Jul 04 2011