id:A039653 - OEIS Search Results

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a(0) = 0; for n > 0, a(n) = sigma(n)-1.

+0
4

0, 0, 2, 3, 6, 5, 11, 7, 14, 12, 17, 11, 27, 13, 23, 23, 30, 17, 38, 19, 41, 31, 35, 23, 59, 30, 41, 39, 55, 29, 71, 31, 62, 47, 53, 47, 90, 37, 59, 55, 89, 41, 95, 43, 83, 77, 71, 47, 123, 56, 92, 71, 97, 53, 119, 71, 119, 79, 89, 59, 167, 61, 95, 103, 126, 83, 143, 67, 125, 95 (list; graph; listen)

	OFFSET	`0,3`
	COMMENT	`Call an integer k between 1 and n a "semi-divisor" of n if n leaves a remainder of 1 when divided by k, i.e. n == 1 (mod k). a(n) gives the sum of the semi-divisors of n+1. - Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Sep 11 2002`
	FORMULA	`a(p) = p for p prime`
	CROSSREFS	`Cf. A000005, A039649-A039656, A032741.` `Sequence in context: A077320 A019565 A133477 this_sequence A106379 A001634 A095113` `Adjacent sequences: A039650 A039651 A039652 this_sequence A039654 A039655 A039656`
	KEYWORD	`nonn`
	AUTHOR	`David W. Wilson (davidwwilson(AT)comcast.net)`

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Last modified November 23 17:09 EST 2009. Contains 167438 sequences.

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