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A005231 Odd abundant numbers. +0
15
945, 1575, 2205, 2835, 3465, 4095, 4725, 5355, 5775, 5985, 6435, 6615, 6825, 7245, 7425, 7875, 8085, 8415, 8505, 8925, 9135, 9555, 9765, 10395, 11025, 11655, 12285, 12705, 12915, 13545, 14175, 14805, 15015, 15435, 16065, 16695, 17325, 17955 (list; graph; listen)
OFFSET

1,1

REFERENCES

L. E. Dickson, Amer. J. Math., 35 (1913), 413-426.

W. Dunham, Euler: The Master of Us All, The Mathematical Association of America Inc., Washington, D.C., 1999, p. 13.

R. K. Guy, Unsolved Problems in Number Theory, B2.

LINKS

T. D. Noe, Table of n, a(n) for n=1..1000

Walter Nissen, Abundancy : Some Resources

Jill Britton, Perfect Number Analyzer.

PROGRAM

(PARI) je=[ ]; forstep(n=1, 15000, 2, x=sigma(n); if(x>(2*n), je=concat(je, n))); je

CROSSREFS

Cf. A006038, A005101, A064001.

Sequence in context: A133814 A104438 A125013 this_sequence A006038 A127667 A109729

Adjacent sequences: A005228 A005229 A005230 this_sequence A005232 A005233 A005234

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

More terms from James A. Sellers (sellersj(AT)math.psu.edu)

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Last modified December 5 08:23 EST 2009. Contains 170348 sequences.


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