

A117004


a(n) = sigma(n)  A079667(n).


8



1, 2, 2, 4, 2, 6, 2, 6, 5, 6, 2, 12, 2, 6, 8, 10, 2, 12, 2, 14, 8, 6, 2, 20, 7, 6, 8, 14, 2, 22, 2, 14, 8, 6, 12, 26, 2, 6, 8, 24, 2, 24, 2, 14, 18, 6, 2, 32, 9, 16, 8, 14, 2, 24, 12, 28, 8, 6, 2, 42, 2, 6, 22, 22, 12, 24, 2, 14, 8, 30, 2, 48, 2, 6, 18, 14, 16, 24, 2, 40, 17, 6, 2, 46, 12, 6, 8, 30
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OFFSET

1,2


REFERENCES

H. J. S. Smith, Report on the Theory of Numbers, reprinted in Vol. 1 of his Collected Math. Papers, Chelsea, NY, 1979, see p. 322.


LINKS

Seiichi Manyama, Table of n, a(n) for n = 1..10000


FORMULA

G.f.: sum(n>=1, n*x^(n^2)*(1+x^n)/(1x^n) ). [Joerg Arndt, Jan 30 2011]
a(n) = Sum_{dn} min(d, n/d).  Seiichi Manyama, Dec 27 2017


PROG

(PARI) {a(n) = sumdiv(n, d, min(d, n/d))} \\ Seiichi Manyama, Dec 27 2017


CROSSREFS

Cf. A000203, A079667.
Sequence in context: A270492 A002322 A127835 * A128982 A096216 A121599
Adjacent sequences: A117001 A117002 A117003 * A117005 A117006 A117007


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, Apr 15 2006


STATUS

approved



