id:A117637 - OEIS Search Results

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Least odd k such that (k*2^n)^2+k*2^n-1 is the first of twin primes with n>0.

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1, 5, 1, 11, 9, 89, 25, 359, 187, 11, 145, 309, 559, 47, 115, 41, 87, 1169, 271, 41, 565, 1005, 1231, 245, 783, 185, 61, 431, 153, 1205, 423, 465, 2547, 1257, 891, 351, 25, 945, 937, 431, 453, 4221, 2763, 251, 783, 1761, 1381, 2493, 2125, 5241, 2871, 255, 4507 (list; graph; listen)

	OFFSET	`1,2`
	EXAMPLE	`(12^1)^2+12^1-1=5, 5 and 7 twin primes so k(1)=1` `(12^2)^2+12^2-1=19 prime but 21 not prime` `(32^2)^2+32^2-1=155 not prime` `(52^2)^2+52^2-1=419, 419 and 421 twin primes so k(2)=5`
	CROSSREFS	`Sequence in context: A131782 A075677 A051853 this_sequence A113261 A132000 A132001` `Adjacent sequences: A117634 A117635 A117636 this_sequence A117638 A117639 A117640`
	KEYWORD	`nonn`
	AUTHOR	`Pierre CAMI (pierrecami(AT)tele2.fr), Apr 09 2006`

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Last modified November 18 20:14 EST 2008. Contains 147244 sequences.

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