id:A153440 - OEIS Search Results

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

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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; listen)

	OFFSET	`1,2`
	COMMENT	`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 this_sequence A037744 A037625 A110679` `Adjacent sequences: A153437 A153438 A153439 this_sequence A153441 A153442 A153443`
	KEYWORD	`nonn`
	AUTHOR	`Pierre CAMI (pierre-cami(AT)orange.fr), Dec 26 2008`

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Last modified December 8 08:31 EST 2009. Contains 170430 sequences.

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