OFFSET
1,2
COMMENTS
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..745
Index entries for linear recurrences with constant coefficients, signature (0,482,0,-1).
FORMULA
From Max Alekseyev, Oct 19 2008: (Start)
For n>=5, a(n) = 482*a(n-2) - a(n-4).
a(2n) = (-60 + 17*sqrt(30))/120 * (11 + 2*sqrt(30))^(2n) + (-60 - 17*sqrt(30))/120 * (11 - 2*sqrt(30))^(2n).
a(2n+1) = (60 + 17*sqrt(30))/120 * (11 + 2*sqrt(30))^(2n) + (60 - 17*sqrt(30))/120 * (11 - 2*sqrt(30))^(2n). (End)
MATHEMATICA
LinearRecurrence[{0, 482, 0, -1}, {1, 133, 615, 64107}, 20] (* Harvey P. Dale, May 12 2014 *)
PROG
(PARI) is(n)=ispolygonal(n^2, 17) \\ Charles R Greathouse IV, Oct 16 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Alexander Adamchuk, Feb 19 2008
EXTENSIONS
Extended by Max Alekseyev, Oct 19 2008
STATUS
approved