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%I #6 Mar 30 2012 18:55:30
%S 1,1,19,951,101126,19471950,6120757875,2923391598085,2012458144311874,
%T 1917251981582592942,2447403154245760930044,4077096587506331113785984,
%U 8671231633412537292307441446,23111533287530979373465097259402
%N Unsigned sum of a triple diagonal product of Stirling numbers of the first kind.
%F a(n) = sum(abs(stirling1(n,k)*stirling1(n+1,k+1)*stirling1(n+2,k+2)),k=0..n).
%t Table[Sum[Abs[StirlingS1[n,k]StirlingS1[n+1,k+1]StirlingS1[n+2,k+2]],{k,0,n}],{n,0,100}]
%o (Maxima) makelist(sum(abs(stirling1(n,k)*stirling1(n+1,k+1)*stirling1(n+2,k+2)),k,0,n),n,0,24);
%K nonn
%O 0,3
%A _Emanuele Munarini_, Jul 04 2011