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A064840
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tau(n)*sigma(n).
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4
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1, 6, 8, 21, 12, 48, 16, 60, 39, 72, 24, 168, 28, 96, 96, 155, 36, 234, 40, 252, 128, 144, 48, 480, 93, 168, 160, 336, 60, 576, 64, 378, 192, 216, 192, 819, 76, 240, 224, 720, 84, 768, 88, 504, 468, 288, 96, 1240, 171, 558, 288, 588, 108, 960, 288, 960, 320, 360
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| Dirichlet convolution of A034761 with (the Dirichlet inverse of A037213). - R. J. Mathar, Feb 11 2011
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LINKS
| Harry J. Smith, Table of n, a(n) for n=1,...,1000
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FORMULA
| Multiplicative with a(p^e) = (p^(e+1)-1)*(e+1)/(p-1). a(n) = 1/2*Sum_{i|n, j|n} (i+j).
Dirichlet g.f. (zeta(s)*zeta(s-1))^2/zeta(2s-1). - R. J. Mathar, Feb 11 2011
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EXAMPLE
| (MAGMA) [ NumberOfDivisors(n)*SumOfDivisors(n) : n in [1..40]];
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MAPLE
| with(numtheory): seq(sigma(n)*tau(n), n=1..58) ; - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jun 04 2008
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PROG
| (PARI) { for (n=1, 1000, a=numdiv(n)*sigma(n); write("b064840.txt", n, " ", a) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Sep 28 2009]
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CROSSREFS
| Cf. A000005, A000203, A007503.
Sequence in context: A191697 A096524 A083595 * A084962 A024306 A024868
Adjacent sequences: A064837 A064838 A064839 * A064841 A064842 A064843
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KEYWORD
| mult,nonn
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AUTHOR
| Vladeta Jovovic (vladeta(AT)eunet.rs), Oct 25 2001
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