login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A051001 Sum of 4th powers of odd divisors of n. 8
1, 1, 82, 1, 626, 82, 2402, 1, 6643, 626, 14642, 82, 28562, 2402, 51332, 1, 83522, 6643, 130322, 626, 196964, 14642, 279842, 82, 391251, 28562, 538084, 2402, 707282, 51332, 923522, 1, 1200644, 83522, 1503652, 6643, 1874162, 130322 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Odd Divisor Function

FORMULA

Dirichlet g.f. (1-2^(4-s))*zeta(s)*zeta(s-4). - R. J. Mathar, Apr 06 2011

G.f.: Sum_{k>=1} (2*k - 1)^4*x^(2*k-1)/(1 - x^(2*k-1)). - Ilya Gutkovskiy, Jan 04 2017

a(n) = A001159(A000265(n)). - Robert Israel, Jan 05 2017

MAPLE

f:= proc(n) add(x^4, x = numtheory:-divisors(n/2^padic:-ordp(n, 2))) end proc:

map(f, [$1..100]); # Robert Israel, Jan 05 2017

MATHEMATICA

Table[Total[Select[Divisors[n], OddQ]^4], {n, 40}] (* Harvey P. Dale, Oct 02 2014 *)

PROG

(PARI) a(n) = sumdiv(n , d, (d%2)*d^4); \\ Michel Marcus, Jan 14 2014

CROSSREFS

Cf. A000265, A000593, A001227, A001159, A050999, A051000, A051002.

Sequence in context: A116268 A128838 A231484 * A033402 A143757 A038008

Adjacent sequences:  A050998 A050999 A051000 * A051002 A051003 A051004

KEYWORD

nonn,mult,look

AUTHOR

Eric W. Weisstein

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 22 21:09 EDT 2018. Contains 316505 sequences. (Running on oeis4.)