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 (15,-90,270,-405,243).
FORMULA
a(n) = 3^n*(n^4 + 42*n^3 + 515*n^2 + 2034*n + 1944)/1944.
G.f.: (1 - 2*x)^4/(1 - 3*x)^5.
E.g.f.: (24 + 96*x + 72*x^2 + 16*x^3 + x^4)*exp(3*x)/24. - G. C. Greubel, Oct 18 2018
MATHEMATICA
LinearRecurrence[{15, -90, 270, -405, 243}, {1, 7, 39, 193, 886}, 50] (* G. C. Greubel, Oct 18 2018 *)
PROG
(PARI) x='x+O('x^30); Vec((1-2*x)^4/(1-3*x)^5) \\ G. C. Greubel, Oct 18 2018
(Magma) m:=30; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!((1-2*x)^4/(1-3*x)^5)); // G. C. Greubel, Oct 18 2018
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paul Barry, Mar 30 2003
STATUS
approved