OFFSET
3,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 3..1000
Index entries for linear recurrences with constant coefficients, signature (20,-160,656,-1456,1664,-768).
FORMULA
G.f.: (96*x^6-256*x^5+298*x^4-201*x^3+75*x^2-14*x+1)*x^3 / ((6*x-1) *(4*x-1)^2 *(2*x-1)^3).
For n>3, a(n) = 2^(n-7)*3^(n-1) + (n-2)*2^(2*n-8) + (n^2 - 3*n + 1)*2^(n-7). - Vaclav Kotesovec, Jul 15 2021
MATHEMATICA
Drop[CoefficientList[Series[(96x^6-256x^5+298x^4-201x^3+75x^2-14x+1)x^3/((6x-1)(4x-1)^2 (2x-1)^3), {x, 0, 30}], x], 3] (* Harvey P. Dale, Jun 11 2024 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Alois P. Heinz, Jul 13 2021
STATUS
approved