OFFSET
1,1
LINKS
Colin Barker, Table of n, a(n) for n = 1..163
Index entries for linear recurrences with constant coefficients, signature (1331715,-1331715,1).
FORMULA
a(n) = (A001653(4*n-1)^2-1)/24.
G.f.: -x*(x^2+41580*x+35) / ((x-1)*(x^2-1331714*x+1)). - Colin Barker, Jun 18 2015
EXAMPLE
a(2) = (A001653(7)^2-1)/24 = (33461^2-1)/24 = 46651605.
MATHEMATICA
LinearRecurrence[{1331715, -1331715, 1}, {35, 46651605, 62126595542551}, 20] (* Harvey P. Dale, Aug 04 2020 *)
PROG
(PARI) Vec(-x*(x^2+41580*x+35)/((x-1)*(x^2-1331714*x+1)) + O(x^20)) \\ Colin Barker, Jun 18 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Franz Vrabec, Aug 26 2006
STATUS
approved