A063966 - OEIS

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A063966

Number of Abelian groups of order <= n.

1, 2, 3, 5, 6, 7, 8, 11, 13, 14, 15, 17, 18, 19, 20, 25, 26, 28, 29, 31, 32, 33, 34, 37, 39, 40, 43, 45, 46, 47, 48, 55, 56, 57, 58, 62, 63, 64, 65, 68, 69, 70, 71, 73, 75, 76, 77, 82, 84, 86, 87, 89, 90, 93, 94, 97, 98, 99, 100, 102, 103, 104, 106, 117, 118, 119, 120, 122 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,2`
	LINKS	`Eric Weisstein's World of Mathematics, Abelian Group` `B. Horvat, G. Jaklic and T. Pisanski, On the number of Hamiltonian groups`
	MAPLE	with(combinat): readlib(ifactors): total := 0: for n from 1 to 100 do ans := 1: for i from 1 to nops(ifactors(n)[2]) do ans := ans*numbpart(ifactors(n)[2][i][2]) od: printf(`%d, `, total+ans): total := total+ans: od:
	CROSSREFS	`Partial sums of A000688.` `Cf. A063756.` `Sequence in context: A094180 A116545 A140661 * A123030 A063752 A191893` `Adjacent sequences: A063963 A063964 A063965 * A063967 A063968 A063969`
	KEYWORD	`nonn`
	AUTHOR	`Ahmed Fares (ahmedfares(AT)my-deja.com), Sep 04 2001`
	EXTENSIONS	`More terms from James A. Sellers (sellersj(AT)math.psu.edu), Sep 26 2001`

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Last modified February 12 03:59 EST 2012. Contains 205360 sequences.