The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A279395 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A279395

a(n) = Sum_{ d >= 1, d divides n} (-1)^(n-d)*d^4.
(history; published version)

#17 by Charles R Greathouse IV at Thu Sep 08 08:46:18 EDT 2022

PROG

(MAGMAMagma) [&+[(-1)^(n-d)*d^4:d in Divisors(n)]:n in [1..40]]; // Marius A. Burtea, Aug 17 2019

Discussion

Thu Sep 08

08:46

OEIS Server: https://oeis.org/edit/global/2944

#16 by Alois P. Heinz at Sat Aug 17 15:42:32 EDT 2019

STATUS

reviewed

approved

#15 by Michel Marcus at Sat Aug 17 11:51:13 EDT 2019

STATUS

proposed

reviewed

#14 by Marius A. Burtea at Sat Aug 17 11:47:45 EDT 2019

STATUS

editing

proposed

#13 by Marius A. Burtea at Sat Aug 17 11:47:41 EDT 2019

PROG

(MAGMA) [&+[(-1)^(n-d)*d^4:d in Divisors(n)]:n in [1..40]]; // Marius A. Burtea, Aug 17 2019

STATUS

proposed

editing

#12 by Amiram Eldar at Sat Aug 17 11:37:18 EDT 2019

STATUS

editing

proposed

#11 by Amiram Eldar at Sat Aug 17 11:19:07 EDT 2019

LINKS

Amiram Eldar, <a href="/A279395/b279395.txt">Table of n, a(n) for n = 1..10000</a>

MATHEMATICA

f[p_, e_] := If[p == 2, (2^(4*(e + 1)) - 31)/15, (p^(4*(e + 1)) - 1)/(p^4 - 1)]; a[1] = 1; a[n_] := Times @@ (f @@@ FactorInteger[n]); Array[a, 40] (* Amiram Eldar, Aug 17 2019 *)

STATUS

approved

editing

#10 by N. J. A. Sloane at Fri Nov 23 14:48:20 EST 2018

STATUS

editing

approved

#9 by N. J. A. Sloane at Fri Nov 23 14:48:18 EST 2018

LINKS

<a href="/index/Ge#Glaisher">Index entries for sequences mentioned by Glaisher</a>

STATUS

approved

editing

#8 by N. J. A. Sloane at Fri Nov 23 13:32:32 EST 2018

STATUS

editing

approved