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A147975
a(n) = 4^n-3^n-2^n-1.
6
-2, -2, 2, 28, 158, 748, 3302, 14068, 58718, 241948, 988502, 4015108, 16241678, 65506348, 263636102, 1059360148, 4251855038, 17050597948, 68331794102, 273715121188, 1096023794798, 4387584060748, 17560800790502, 70274592610228
OFFSET
1,1
FORMULA
G.f.: 2*x*(19*x^3-24*x^2+9*x-1)/((x-1)*(2*x-1)*(3*x-1)*(4*x-1)). - Colin Barker, Oct 29 2012
MATHEMATICA
lst={}; Do[p=4^n-3^n-2^n-1^n; AppendTo[lst, p], {n, 0, 5!}]; lst
LinearRecurrence[{10, -35, 50, -24}, {-2, -2, 2, 28}, 40] (* Harvey P. Dale, Nov 08 2016 *)
PROG
(PARI) a(n)=4^n-3^n-2^n-1 \\ Charles R Greathouse IV, Oct 07 2015
CROSSREFS
KEYWORD
sign,easy
AUTHOR
STATUS
approved