OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..2000
Index entries for linear recurrences with constant coefficients, signature (7,-18,20,-8).
FORMULA
a(n) = (n^2+37*n+324)*2^(n-2)-80.
a(n) = 7*a(n-1)-18*a(n-2)+20*a(n-3)-8*a(n-4). - Colin Barker, Feb 25 2015
G.f.: (352*x^3-367*x^2+94*x+1) / ((x-1)*(2*x-1)^3). Colin Barker, Feb 25 2015
MATHEMATICA
LinearRecurrence[{7, -18, 20, -8}, {1, 101, 322, 808}, 30] (* Harvey P. Dale, Jan 08 2023 *)
PROG
(Magma) [(n^2+37*n+324)*2^(n-2)-80: n in [0..30]]
(PARI) a(n)=(n^2+37*n+324)<<(n-2)-80 \\ Charles R Greathouse IV, Dec 27 2011
(PARI) Vec((352*x^3-367*x^2+94*x+1)/((x-1)*(2*x-1)^3) + O(x^100)) \\ Colin Barker, Feb 25 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Sep 25 2011
STATUS
approved