id:A072668 - OEIS Search Results

Search: id:A072668

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Numbers one less than composite numbers.

+0
9

3, 5, 7, 8, 9, 11, 13, 14, 15, 17, 19, 20, 21, 23, 24, 25, 26, 27, 29, 31, 32, 33, 34, 35, 37, 38, 39, 41, 43, 44, 45, 47, 48, 49, 50, 51, 53, 54, 55, 56, 57, 59, 61, 62, 63, 64, 65, 67, 68, 69, 71, 73, 74, 75, 76, 77, 79, 80, 81, 83, 84, 85, 86, 87, 89, 90, 91, 92, 93, 94, 95 (list; graph; listen)

	OFFSET	`1,1`
	COMMENT	`Complement of A006093 (primes minus 1); numbers which can be written as ij+i+j, 0<i<=j: A072670(a(n))>0 for n>1; a(n)! is divisible by a(n)(a(n)+1)/2, see A060462.` `A072668 U A006093 = A000027. [From Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Oct 22 2009]`
	FORMULA	`a(n) = A002808(n) - 1.` `a(n)=2*A002808(n)-A079696(n). [From Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Oct 22 2009]`
	CROSSREFS	`Cf. A066938, A072672.` `Cf. A000027, A006093, A079696. [From Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Oct 22 2009]` `Sequence in context: A134407 A144724 A060462 this_sequence A062958 A153309 A047486` `Adjacent sequences: A072665 A072666 A072667 this_sequence A072669 A072670 A072671`
	KEYWORD	`nonn`
	AUTHOR	`Henry Bottomley (se16(AT)btinternet.com), Apr 11 2001`

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.

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