id:A046915 - OEIS Search Results

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Sum of divisors of 10^n.

+0
3

1, 18, 217, 2340, 24211, 246078, 2480437, 24902280, 249511591, 2497558338, 24987792457, 249938963820, 2499694822171, 24998474116998, 249992370597277, 2499961853010960, 24999809265103951, 249999046325618058, 2499995231628286897 (list; graph; listen)

	OFFSET	`0,2`
	COMMENT	`A072692(n) = A049000(n) + A046915(n).`
	FORMULA	`1/4(2^(n+1)-1)(5^(n+1)-1). E.g. a(1)=1/4(2^2-1)(5^2-1)=18. - Vladeta Jovovic (vladeta(AT)eunet.rs), Dec 18 2001`
	EXAMPLE	`At 10^1 the factors are 1, 2, 5, 10. The sum of these factors is 18: 1 + 2 + 5 + 10.`
	CROSSREFS	`Cf. A000203 (sigma(n)), A049000, A072692.` `Sequence in context: A019757 A021503 A025470 this_sequence A041616 A019333 A021454` `Adjacent sequences: A046912 A046913 A046914 this_sequence A046916 A046917 A046918`
	KEYWORD	`easy,nonn`
	AUTHOR	`Enoch Haga (Enokh(AT)comcast.net)`

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

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