OFFSET
1,1
LINKS
Paul D. Hanna, Table of n, a(n) for n = 1..40
FORMULA
a(n) == 2 (mod 32).
a(n) = (1+sqrt(2))^(n^2) + (1-sqrt(2))^(n^2).
Logarithmic derivative of A165937.
MATHEMATICA
Simplify[Table[(1 + Sqrt[2])^(n^2) + (1 - Sqrt[2])^(n^2), {n, 1, 7}]] (* G. C. Greubel, Apr 18 2016 *)
PROG
(PARI) {a(n)=polcoeff(2*(1-x)/(1-2*x-x^2 +x*O(x^(n^2))), n^2)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Oct 18 2009
STATUS
approved