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A051377 Sum of exponential divisors (or e-divisors) of n. +0
11
1, 2, 3, 6, 5, 6, 7, 10, 12, 10, 11, 18, 13, 14, 15, 22, 17, 24, 19, 30, 21, 22, 23, 30, 30, 26, 30, 42, 29, 30, 31, 34, 33, 34, 35, 72, 37, 38, 39, 50, 41, 42, 43, 66, 60, 46, 47, 66, 56, 60, 51, 78, 53, 60, 55, 70, 57, 58, 59, 90, 61, 62, 84, 78, 65, 66, 67, 102, 69, 70, 71 (list; graph; listen)
OFFSET

1,2

COMMENT

The e-divisors (or exponential divisors) of x=Product p(i)^r(i) are all numbers of the form Product p(i)^s(i) where s(i) divides r(i) for all i.

REFERENCES

Fabrykowski, J. and Subbarao, M. V., The maximal order and the average order of multiplicative function sigma^(e)(n), in Theorie des nombres (Quebec, PQ, 1987), 201-206, de Gruyter, Berlin, 1989.

Petermann, Y.-F. S. and Wu, J., On the sum of exponential divisors of an integer, Acta Math. Hungar. 77 (1997), 159-175.

LINKS

Eric Weisstein's World of Mathematics, Definition

FORMULA

Multiplicative with a(p^e) = Sum_{d|e} p^d. - Vladeta Jovovic (vladeta(AT)Eunet.yu), Apr 23 2002

EXAMPLE

a(8)=10 because 2 and 2^3 are e-divisors of 8, and 2+2^3=10.

CROSSREFS

Cf. A051378, A049419.

Adjacent sequences: A051374 A051375 A051376 this_sequence A051378 A051379 A051380

Sequence in context: A093783 A096861 A118738 this_sequence A057723 A142151 A003968

KEYWORD

nonn,easy,nice,mult

AUTHOR

Yasutoshi Kohmoto (zbi74583(AT)boat.zero.ad.jp)

EXTENSIONS

More terms from Jud McCranie (j.mccranie(AT)comcast.net), May 29 2000

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Last modified October 15 09:18 EDT 2008. Contains 145015 sequences.


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