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A085603
(2n)^(2n) + 1.
0
2, 5, 257, 46657, 16777217, 10000000001, 8916100448257, 11112006825558017, 18446744073709551617, 39346408075296537575425, 104857600000000000000000001
OFFSET
0,1
COMMENTS
a(n) is never a perfect square because (2n)^(2n) is a positive square and the only squares that differ by 1 are 0 and 1. Sierpinski numbers are n^n+1. Hence this sequence is a subset of the Sierpinski numbers (A014566). - T. D. Noe, Mar 31 2006
PROG
(PARI) forstep(x=0, 20, 2, print1(x^x+1" "))
CROSSREFS
Sequence in context: A175977 A367673 A121270 * A309675 A042341 A300900
KEYWORD
easy,nonn
AUTHOR
Cino Hilliard, Jul 07 2003
STATUS
approved