A034904 Related to sept-factorial numbers A045754.

1, 28, 980, 37730, 1531838, 64337196, 2766499428, 121034349975, 5365856182225, 240390356963680, 10861273400995360, 494187939745288880, 22618601857572837200, 1040455685448350511200, 48069052667713793617440

Offset

1,2

Comments

Convolution of A034835(n-1) with A025752(n), n >= 1.

Links

Michael De Vlieger, Table of n, a(n) for n = 1..594

Elżbieta Liszewska, Wojciech Młotkowski, Some relatives of the Catalan sequence, arXiv:1907.10725 [math.CO], 2019.

Index entries for sequences related to factorial numbers

Formula

a(n) = 7^(n-1)*A045754(n)/n!, A045754(n)=(7*n-6)(!^7) := product(7*j-6, j=1..n); G.f. (-1+(1-49*x)^(-1/7))/7.

D-finite with recurrence: n*a(n) +7*(-7*n+6)*a(n-1)=0. - R. J. Mathar, Jan 28 2020

Mathematica

CoefficientList[Series[(Power[1-49x, (-7)^-1]-1)/7, {x, 0, 30}], x] (* Harvey P. Dale, Aug 23 2011 *)

Crossrefs

Cf. A045754, A034835, A025752.

Sequence in context: A203135 A097579 A091549 * A189995 A228689 A218480

Adjacent sequences: A034901 A034902 A034903 * A034905 A034906 A034907

Keyword

easy,nonn

Author

Wolfdieter Lang

Status

approved