OFFSET
1,1
LINKS
Harry J. Smith, Table of n, a(n) for n = 1..500
FORMULA
If n is not congruent to 1 mod 4, a(n) = 1. If n is congruent to 1 mod 4, a(n) = 2^n + 1.
G.f.: (-16x^5-2x^2+3x)/(16x^4-1)/(x-1). - Ralf Stephan, Mar 12 2003
MATHEMATICA
Table[If[Mod[n, 4]==1, 2^n+1, 1], {n, 80}] (* Harvey P. Dale, Jun 30 2022 *)
PROG
(PARI) { for (n=1, 500, write("b066827.txt", n, " ", gcd(2^((n*(n+1)/2)) + 1, 2^n + 1)) ) } \\ Harry J. Smith, Mar 30 2010
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Jan 20 2002
STATUS
approved