

A115964


Denominator of sum_{i=1..n} 1/prime(i)^3.


6



8, 216, 27000, 9261000, 12326391000, 27081081027000, 133049351085651000, 912585499096480209000, 11103427767506874702903000, 270801499821725167129101267000, 8067447481189014453943055845197000
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OFFSET

1,1


COMMENTS

Numerators are in A115963.
Also the primorials cubed.  Reikku Kulon, Sep 18 2008


LINKS

Table of n, a(n) for n=1..11.


FORMULA

a(n) = denominator of sum_{i=1..n} 1/A000040(i)^3.
a(n) = A002110(n)^3.  Reikku Kulon, Sep 18 2008


EXAMPLE

1/8, 35/216, 4591/27000, 1601713/9261000, 2141141003/12326391000, 4716413174591/27081081027000.


MATHEMATICA

a[n_]:=Product[Prime[i]^3, {i, 1, n}]; (* Vladimir Joseph Stephan Orlovsky, Dec 05 2008 *)


CROSSREFS

Cf. A115963 (numerators).
Cf. A024451 (numerator of sum_{i=1..n} 1/prime(i)), A002110 (primorial, also denominator of sum_{i=1..n} 1/prime(i)), A061015 (numerator of sum_{i=1..n} 1/prime(i)^2).
Cf. A000040, A075986/A075987, A106830/A034386.
Cf. A061742, A100778.  Reikku Kulon, Sep 18 2008
Sequence in context: A000442 A268471 A226524 * A245591 A247539 A188680
Adjacent sequences: A115961 A115962 A115963 * A115965 A115966 A115967


KEYWORD

easy,frac,nonn


AUTHOR

Jonathan Vos Post, Mar 14 2006


STATUS

approved



