A013603 - OEIS

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A013603

2^n-prevprime(2^n).

1, 1, 3, 1, 3, 1, 5, 3, 3, 9, 3, 1, 3, 19, 15, 1, 5, 1, 3, 9, 3, 15, 3, 39, 5, 39, 57, 3, 35, 1, 5, 9, 41, 31, 5, 25, 45, 7, 87, 21, 11, 57, 17, 55, 21, 115, 59, 81, 27, 129, 47, 111, 33, 55, 5, 13, 27, 55, 93, 1, 57, 25, 59, 49, 5, 19, 23, 19, 35, 231, 93, 69, 35, 97, 15 (list; graph; refs; listen; history; internal format)

	OFFSET	`2,3`
	COMMENTS	`If a(n)=1, then n is prime and 2^n-1 is a Mersenne prime. - Franz Vrabec (franz.vrabec(AT)aon.at), Sep 27 2005`
	LINKS	`T. D. Noe, Table of n, a(n) for n=2..5000` `V. Danilov, Table for large n`
	MAPLE	`seq(2^i-prevprime(2^i), i=2..100);`
	CROSSREFS	`Cf. A014210.` `Sequence in context: A053575 A103790 A193583 * A157892 A146907 A126212` `Adjacent sequences: A013600 A013601 A013602 * A013604 A013605 A013606`
	KEYWORD	`nonn`
	AUTHOR	`James Kilfiger (mapdn(AT)csv.warwick.ac.uk)`

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Last modified February 16 09:27 EST 2012. Contains 205904 sequences.