id:A121371 - OEIS Search Results

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Least number k such that (k*M(n))^2 + k*M(n) - 1 and (k*M(n))^2 + k*M(n) + 1 are twin primes with M(i)=i-th Mersenne prime.

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1, 3, 5, 8, 99, 275, 278, 409, 96, 1538, 1253, 15858, 189168, 119552, 221444, 1047122, 3571449 (list; graph; listen)

	OFFSET	`1,2`
	EXAMPLE	`M(2)=2^3-1=7` `7^2+7-1=55 composite` `(27)^2+27-1=209 composite` `(37)^2+37-1=461 prime, 461 and 463 are twin primes so k(2)=3`
	CROSSREFS	`Cf. A121370.` `Sequence in context: A108460 A027520 A109342 this_sequence A067094 A058642 A141251` `Adjacent sequences: A121368 A121369 A121370 this_sequence A121372 A121373 A121374`
	KEYWORD	`hard,more,nonn`
	AUTHOR	`Pierre CAMI (pierrecami(AT)tele2.fr), Jul 24 2006`

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Last modified December 10 12:37 EST 2009. Contains 170569 sequences.