OFFSET
0,2
COMMENTS
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (20,-150,500,-625)
FORMULA
a(n) = 5^n*(n^3 + 42*n^2 + 407*n + 750)/750.
G.f.: (1 - 4*x)^3/(1 - 5*x)^4.
E.g.f.: (6 + 18*x + 9*x^2 + x^3)*exp(5*x)/6. - G. C. Greubel, Oct 18 2018
MATHEMATICA
LinearRecurrence[{20, -150, 500, -625}, {1, 8, 58, 396}, 50] (* G. C. Greubel, Oct 18 2018 *)
PROG
(PARI) x='x+O('x^30); Vec((1-4*x)^3/(1-5*x)^4) \\ G. C. Greubel, Oct 18 2018
(Magma) m:=30; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!((1-4*x)^3/(1-5*x)^4)); // G. C. Greubel, Oct 18 2018
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paul Barry, Mar 30 2003
STATUS
approved