A187658 Binomial convolution of the (signless) central Stirling numbers of the first kind (A187646).

1, 2, 24, 516, 16064, 655840, 33157240, 1999679696, 140128848384, 11189643689088, 1003005057594240, 99725721676986240, 10892178742891589792, 1296379044138734510656, 166999512859041432577280, 23149972436862049305233280

Offset

0,2

Links

Table of n, a(n) for n=0..15.

Formula

a(n) = sum(binomial(n,k)s(2k,k)s(2n-2k,n-k)),k=0..n)

Maple

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

Mathematica

Table[Sum[Binomial[n, k]Abs[StirlingS1[2k, k]]Abs[StirlingS1[2n - 2k, n - k]], {k, 0, n}], {n, 0, 15}]

Prog

(Maxima) makelist(sum(binomial(n, k)*abs(stirling1(2*k, k))*abs(stirling1(2*n-2*k, n-k)), k, 0, n), n, 0, 12);

Crossrefs

Cf. A187646

Sequence in context: A012236 A186414 A359848 * A138450 A262009 A367271

Adjacent sequences: A187655 A187656 A187657 * A187659 A187660 A187661

Keyword

nonn,easy

Author

Emanuele Munarini, Mar 12 2011

Status

approved