id:A090945 - OEIS Search Results

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Harmonic numbers (A001599) which are not perfect (A000396).

+0
4

1, 140, 270, 672, 1638, 2970, 6200, 8190, 18600, 18620, 27846, 30240, 32760, 55860, 105664, 117800, 167400, 173600, 237510, 242060, 332640, 360360, 539400, 695520, 726180, 753480, 950976, 1089270, 1421280, 1539720 (list; graph; listen)

	OFFSET	`1,2`
	REFERENCES	`T. Goto and S. Shibata, All numbers whose positive divisors have integral harmonic mean up to 300, Math. Comput. 73 (2004), 475-491.` `R. K. Guy, Unsolved Problems in Number Theory, B2.`
	CROSSREFS	`Cf. A001599, A003601. Different from A007340.` `For the associated harmonic means, see A102408.` `Sequence in context: A108317 A114825 A131492 this_sequence A140798 A010080 A133711` `Adjacent sequences: A090942 A090943 A090944 this_sequence A090946 A090947 A090948`
	KEYWORD	`nonn`
	AUTHOR	`N. J. A. Sloane (njas(AT)research.att.com), Feb 28 2004`

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Last modified November 24 23:16 EST 2009. Contains 167481 sequences.

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