id:A124052 - OEIS Search Results

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Sum from 1 to n of all factors of primes less than n such that the power of any factor (p) never exceeds log(n) base p.

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1, 3, 12, 28, 168, 168, 1344, 2880, 9360, 9360, 112320, 112320, 1572480, 1572480, 1572480, 3249792, 58496256, 58496256, 1169925120, 1169925120, 1169925120, 1169925120, 28078202880, 28078202880, 145070714880, 145070714880 (list; graph; listen)

	OFFSET	`1,2`
	COMMENT	`a(n) > a(n-1) implies n is either a prime or the power of a prime.`
	FORMULA	`a(n) = a(n-1)(1+n*(P-1)/(n-1)) ( If n is the power of any prime (P) ) a(n) = A(n-1) If n is not the power of any prime`
	EXAMPLE	`A(5) = A(6) = (1+2+4)(1+3)(1+5) = 1 + 2 + 3 + 4 + 5 + 6 + 10 + 12 + 15 + 20 + 30 + 60`
	CROSSREFS	`Sequence in context: A005995 A034503 A026557 this_sequence A104353 A001860 A101459` `Adjacent sequences: A124049 A124050 A124051 this_sequence A124053 A124054 A124055`
	KEYWORD	`nonn`
	AUTHOR	`Timothy Frison (frison(AT)gmail.com), Nov 03 2006`

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

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