A090945 - OEIS

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A090945

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

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; refs; listen; history; internal format)

	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 * A140798 A196447 A010080` `Adjacent sequences: A090942 A090943 A090944 * A090946 A090947 A090948`
	KEYWORD	`nonn`
	AUTHOR	`N. J. A. Sloane (njas(AT)research.att.com), Feb 28 2004`

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Last modified February 16 02:51 EST 2012. Contains 205860 sequences.