A091551 Second column (k=3) sequence of array ((7,2)-Stirling2) divided by 14.

1, 228, 83232, 46854720, 38109367296, 42479241412608, 62290218157719552, 116373513947009679360, 270010358636135897235456, 762020881523854021734432768, 2571195906705444158241905836032

Offset

0,2

Links

Table of n, a(n) for n=0..10.

Formula

a(n)= product(5*j+2, j=0..n-1)*(-3*product(5*j+1, j=0..n-1) + product(5*j+3, j=0..n-1))/(3!*14), n>=2. From eq.12 of the Blasiak et al. reference given in A007840 with r=7, s=2, k=3.

a(n)= (5^(2*n))*risefac(2/5, n)*(-3*risefac(1/5, n) + risefac(3/5, n))/(3!*14), n>=2, with risefac(x, n)=Pochhammer(x, n).

E.g.f.: (hypergeom([2/5, 3/5], [], 25*x) - 3*hypergeom([1/5, 2/5], [], 25*x) + 2)/(3!*14).

Crossrefs

Cf. A091550 (second column of (6, 2)-Stirling2 array), A091552 (second column of (8, 2)-Stirling2 array).

Sequence in context: A201238 A220624 A098246 * A033528 A086002 A061783

Adjacent sequences: A091548 A091549 A091550 * A091552 A091553 A091554

Keyword

nonn,easy

Author

Wolfdieter Lang, Feb 13 2004

Status

approved