A082477 - OEIS

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A082477

Number of divisors d of n such that d+1 is also a divisor of n+1.

1, 1, 2, 1, 2, 1, 2, 2, 2, 1, 2, 1, 2, 2, 3, 1, 2, 1, 2, 2, 2, 1, 2, 2, 2, 2, 3, 1, 2, 1, 2, 2, 2, 1, 3, 1, 2, 2, 3, 1, 2, 1, 2, 3, 2, 1, 2, 2, 2, 2, 3, 1, 2, 1, 2, 2, 2, 1, 2, 1, 2, 2, 4, 2, 3, 1, 2, 2, 2, 1, 2, 1, 2, 2, 3, 1, 2, 1, 2, 3, 2, 1, 2, 2, 2, 2, 3, 1, 2, 2, 2, 2, 2, 1, 3, 1, 2, 2, 4, 1, 2, 1, 2, 3, 2 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,3`
	FORMULA	`G.f.: Sum_{k>0} x^k/(1-x^(k*(k+1))). [From Vladeta Jovovic (vladeta(AT)eunet.rs), Apr 21 2010]`
	PROG	`(PARI) a(n)=sumdiv(n, d, if((n+1)%(d+1), 0, 1))`
	CROSSREFS	`Sequence in context: A072410 A072491 A051034 * A036430 A163377 A163109` `Adjacent sequences: A082474 A082475 A082476 * A082478 A082479 A082480`
	KEYWORD	`nonn`
	AUTHOR	`Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 27 2003`

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Last modified February 17 20:50 EST 2012. Contains 206085 sequences.