OFFSET
1,1
COMMENTS
Also even Sierpinski numbers of the first kind.
No term is a square. Moreover, x^x + 1 != k^x, for if it were, we would have a counterexample to Fermat's Last Theorem.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..193
FORMULA
a(n) = (2*n-1)^(2*n-1)+1. - Alois P. Heinz, Feb 27 2020
MATHEMATICA
#^#+1&/@Range[1, 21, 2] (* Harvey P. Dale, Dec 08 2012 *)
PROG
(PARI) forstep(x=1, 20, 2, print1(x^x+1" "))
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Cino Hilliard, Jul 07 2003
STATUS
approved