OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (20,-135,340,-224).
FORMULA
a(n) = (9*8^(n+3) - 14*7^(n+3) + 7*4^(n+3) - 2)/252. - Yahia Kahloune, Jul 05 2013
MATHEMATICA
CoefficientList[Series[1 / ((1 - x) (1 - 4 x) (1 - 7 x) (1 - 8 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 11 2013 *)
LinearRecurrence[{20, -135, 340, -224}, {1, 20, 265, 2940}, 30] (* Harvey P. Dale, Dec 26 2022 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved