A192563 - OEIS

%I #13 May 26 2021 02:23:49

%S 1,2,13,161,3148,87784,3274640,156359874,9252910816,662065322016,

%T 56172251821992,5562573507747288,634574662217269824,

%U 82482896750780978880,12101565966159294983808,1987899464090970683668944,363036441677797499946379776

%N a(n) = Sum_{k=0..n} abs(Stirling1(n+1,k+1))*Stirling2(n+1,k+1)*k!.

%H Stefano Spezia, <a href="/A192563/b192563.txt">Table of n, a(n) for n = 0..270</a>

%t Table[Sum[Abs[StirlingS1[n+1,k+1]]StirlingS2[n+1,k+1]k!,{k,0,n}],{n,0,100}]

%o (Maxima) makelist(sum(abs(stirling1(n+1,k+1))*stirling2(n+1,k+1)*k!,k,0,n),n,0,12);

%Y Diagonal of the array A344639.

%Y Cf. A000142, A008275, A008277, A081048.

%K nonn

%O 0,2

%A _Emanuele Munarini_, Jul 04 2011