OFFSET
0,4
LINKS
Index entries for linear recurrences with constant coefficients, signature (0,7,0,-9,0,7,0,-1).
FORMULA
G.f.: (x^8 - x^7 - 8*x^6 - 6*x^5 + 9*x^4 + 6*x^3 - 6*x^2 + x + 1) / ((x^4 - x^3 - 3*x^2 - x + 1)*(x^4 + x^3 - 3*x^2 + x + 1)). - Colin Barker, Jan 05 2014
MATHEMATICA
f[n_] = Product[(1 + 4*Sin[k*Pi/n]^2 + 16*Sin[k*Pi/n]^4), {k, 1, Floor[(n - 1)/2]}]; a = Table[f[n], {n, 0, 30}]; Round[a]; FullSimplify[ExpandAll[a]]
PROG
(PARI) Vec((x^8-x^7-8*x^6-6*x^5+9*x^4+6*x^3-6*x^2+x+1)/((x^4-x^3-3*x^2-x+1)*(x^4+x^3-3*x^2+x+1)) + O(x^100)) \\ Colin Barker, Jan 05 2014
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Roger L. Bagula and Gary W. Adamson, Nov 26 2008
STATUS
approved