A153440 - OEIS

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A153440

Numbers k such that k^9*(k^9+1)+1 is prime

1, 2, 11, 44, 45, 56, 62, 63, 110, 170, 219, 234, 245, 261, 263, 333, 395, 398, 402, 413, 428, 434, 437, 498, 557, 558, 578, 633, 692, 695, 723, 731, 750, 761, 774, 794, 797, 804, 806, 846, 854, 855, 863, 906, 923, 926, 977, 1046, 1085, 1086 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,2`
	COMMENTS	`Numbers of the form k^n(k^n+1)+1 with n > 0, k > 1 may be primes only if n has the form 3^j When n is even k^(4n)+k^(2n)+1=(k^(2n)+1)^2-(k^n)^2=(k^(2n)+k^n+1)(k^(2n)-k^n+1) so composite But why if n odd > 3 and not a power of 3 k^n(k^n+1)+1 is alway composite ??`
	LINKS	`Pierre CAMI, Table of n, a(n) for n=1,...,38019`
	CROSSREFS	`A153438` `Sequence in context: A050620 A027253 A066058 * A181369 A037744 A037625` `Adjacent sequences: A153437 A153438 A153439 * A153441 A153442 A153443`
	KEYWORD	`nonn`
	AUTHOR	`Pierre CAMI (pierre-cami(AT)bbox.fr), Dec 26 2008`

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Last modified February 16 07:39 EST 2012. Contains 205881 sequences.