OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..445
A. Straub, V. H. Moll, T. Amdeberhan, The p-adic valuation of k-central binomial coefficients, Acta Arith. 140 (1) (2009) 31-41, eq (1.10)
FORMULA
a(n) = 7^n*A045754(n)/n!, n >= 1, A045754(n) = (7*n-6)(!^7) := product(7*j-6, j=1..n); G.f.: (1-49*x)^(-1/7).
D-finite with recurrence: n*a(n) +7*(-7*n+6)*a(n-1)=0. - R. J. Mathar, Jan 28 2020
MATHEMATICA
CoefficientList[Series[1/(1 - 49*x)^(1/7), {x, 0, 50}], x] (* G. C. Greubel, Feb 22 2018 *)
PROG
(PARI) x='x+O('x^30); Vec(1/(1 - 49*x)^(1/7)) \\ G. C. Greubel, Feb 22 2018
(Magma) Q:=Rationals(); R<x>:=PowerSeriesRing(Q, 40); Coefficients(R!(1/(1 - 49*x)^(1/7))) // G. C. Greubel, Feb 22 2018
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
STATUS
approved