OFFSET
0,3
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..239
Index entries for linear recurrences with constant coefficients, signature (9,-35,77,-105,91,-49,15,-2).
FORMULA
G.f.: (1-8*x-34*x^2-223*x^3+337*x^4+526*x^5+120*x^6+x^7) / ((1-2* x)*(1-x)^7). - Vincenzo Librandi, Oct 07 2014
a(n) = 9*a(n-1) -35*a(n-2) +77*a(n-3) -105*a(n-4) +91*a(n-5) -49*a(n-6) +15*a(n-7) -2*a(n-8) for n>7. - Vincenzo Librandi, Oct 07 2014
MATHEMATICA
Table[2^n - n^6, {n, 0, 30}] (* or *) CoefficientList[Series[(1 - 8 x - 34 x^2 - 223 x^3 + 337 x^4 + 526 x^5 + 120 x^6 + x^7)/((1 - 2 x) (1 - x)^7), {x, 0, 30}], x] (* Vincenzo Librandi, Oct 07 2014 *)
LinearRecurrence[{9, -35, 77, -105, 91, -49, 15, -2}, {1, 1, -60, -721, -4080, -15593, -46592, -117521}, 30] (* Harvey P. Dale, Oct 04 2019 *)
PROG
(Magma) [2^n-n^6: n in [0..25]]; // Vincenzo Librandi, Apr 30 2011
(Magma) I:=[1, 1, -60, -721, -4080, -15593, -46592, -117521]; [n le 8 select I[n] else 9*Self(n-1)-35*Self(n-2)+77*Self(n-3)-105*Self(n-4)+91*Self(n-5)-49*Self(n-6)+15*Self(n-7)-2*Self(n-8): n in [1..35]]; // Vincenzo Librandi, Oct 07 2014
CROSSREFS
KEYWORD
sign,easy
AUTHOR
STATUS
approved