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A085602
Numbers of the form (2n+1)^(2n+1) + 1.
1
2, 28, 3126, 823544, 387420490, 285311670612, 302875106592254, 437893890380859376, 827240261886336764178, 1978419655660313589123980, 5842587018385982521381124422, 20880467999847912034355032910568, 88817841970012523233890533447265626
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
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
Bisection of A014566 (odd part).
Sequence in context: A230700 A168554 A152792 * A058502 A080266 A308757
KEYWORD
easy,nonn
AUTHOR
Cino Hilliard, Jul 07 2003
STATUS
approved