A187664 - OEIS

%I #5 Mar 30 2012 18:55:30

%S 1,3,49,1483,67615,4173203,326208269,30880075203,3430574739759,

%T 437145190334383,62803806114813801,10038354053796477099,

%U 1766255133182030548351,339166069936077378326187,70571377417819411767223541

%N Convolution of the (signless) central Lah numbers (A187535) and the (signless) central Stirling numbers of the first kind (A187646).

%F a(n) = sum(Lah(2k,k)s(2n-2k,n-k)),k=0..n)

%p L := n -> if n=0 then 1 else binomial(2*n-1,n-1)*(2*n)!/n! fi;

%p seq(sum(L(k)*abs(combinat[stirling1](2*(n-k),n-k)),k=0..n),n=0..12);

%t L[n_] := If[n == 0, 1, Binomial[2n - 1, n - 1](2n)!/n!]

%t Table[Sum[L[k]Abs[StirlingS1[2n - 2k, n - k]], {k, 0, n}], {n, 0, 14}]

%o (Maxima) L(n):= if n=0 then 1 else binomial(2*n-1,n-1)*(2*n)!/n!;

%o makelist(sum(L(k)*abs(stirling1(2*n-2*k,n-k)),k,0,n),n,0,12);

%Y Cf. A187535, A187646

%K nonn,easy

%O 0,2

%A _Emanuele Munarini_, Mar 12 2011