id:A089017 - OEIS Search Results

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n for which the number consisting of a string of n 3's and a terminal 1 is not prime.

+0
4

8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 40, 41, 42, 43, 44, 45, 46, 47, 48, 50, 51, 52, 53, 54, 55, 56, 57, 58, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 78, 79, 80, 81, 82 (list; graph; listen)

	OFFSET	`1,1`
	COMMENT	`Complement of A055520(n)=A055557(n) - 1. The first n for which {10^(n+1) - 7}/3 is composite is thus n=8,corresponding to 333333331=17*19607843.`
	CROSSREFS	`Cf. A055520, A089018.` `Sequence in context: A004449 A020722 A046037 this_sequence A023391 A115419 A161639` `Adjacent sequences: A089014 A089015 A089016 this_sequence A089018 A089019 A089020`
	KEYWORD	`nonn`
	AUTHOR	`Lekraj Beedassy (blekraj(AT)yahoo.com), Nov 04 2003`

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Last modified November 22 20:51 EST 2009. Contains 167312 sequences.

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