OFFSET
0,3
LINKS
Harvey P. Dale, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (7,-19,25,-16,4).
FORMULA
a(n) = ((n + 2)*2^n - 2*n^2 - 2)/2 for n >= 1. - Charles R Greathouse IV, May 31 2026
MAPLE
gf := (4*x^5 - 9*x^4 + 17*x^3 - 15*x^2 + 6*x - 1)/((2*x - 1)^2*(x - 1)^3):
ser := series(gf, x, 33): seq(coeff(ser, x, n), n=0..31);
MATHEMATICA
CoefficientList[Series[(4x^5-9x^4+17x^3-15x^2+6x-1)/((2x-1)^2(x-1)^3), {x, 0, 40}], x] (* or *) LinearRecurrence[{7, -19, 25, -16, 4}, {1, 1, 3, 10, 31, 86}, 40] (* Harvey P. Dale, Jan 28 2026 *)
PROG
(PARI) a(n)=if(n, (n+2)*2^n/2-n^2-1, 1) \\ Charles R Greathouse IV, May 31 2026
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Peter Luschny, Nov 24 2020
STATUS
approved
