The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A007409 Denominators of Sum_{k=1..n} 1/k^3. (Formerly M4579) 14
 1, 8, 216, 1728, 216000, 24000, 8232000, 65856000, 16003008000, 16003008000, 21300003648000, 21300003648000, 46796108014656000, 46796108014656000, 46796108014656000, 374368864117248000, 1839274229408039424000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Largest prime factor in A007409(n) (n > 1) is A007917(n), occurring always to the power 3. - M. F. Hasler, Nov 10 2006 REFERENCES D. Y. Savio, E. A. Lamagna and S.-M. Liu, Summation of harmonic numbers, pp. 12-20 of E. Kaltofen and S. M. Watt, editors, Computers and Mathematics, Springer-Verlag, NY, 1989. N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS T. D. Noe, Table of n, a(n) for n=1..200 MAPLE A007409:= n->denom(sum(1/k^3, k=1..n)); # M. F. Hasler, Nov 10 2006 MATHEMATICA Table[Denominator[Sum[1/k^3, {k, n}]], {n, 10}] (* Alonso del Arte, Dec 30 2012 *) CROSSREFS Cf. A007408, A007917. Sequence in context: A275023 A163289 A060459 * A195506 A069045 A288323 Adjacent sequences:  A007406 A007407 A007408 * A007410 A007411 A007412 KEYWORD nonn,easy,frac AUTHOR STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified January 26 20:33 EST 2020. Contains 331288 sequences. (Running on oeis4.)