The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A344721 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A344721

a(n) = Sum_{k=1..n} (-1)^(k+1) * floor(n/k)^3.
(history; published version)

#22 by Susanna Cuyler at Fri May 28 17:17:52 EDT 2021

STATUS

proposed

approved

#21 by Seiichi Manyama at Fri May 28 12:09:44 EDT 2021

STATUS

editing

proposed

#20 by Seiichi Manyama at Fri May 28 12:06:24 EDT 2021

LINKS

Seiichi Manyama, <a href="/A344721/b344721.txt">Table of n, a(n) for n = 1..10000</a>

STATUS

approved

editing

#19 by Vaclav Kotesovec at Fri May 28 02:51:43 EDT 2021

STATUS

editing

approved

#18 by Vaclav Kotesovec at Fri May 28 02:51:35 EDT 2021

MATHEMATICA

Accumulate[Table[-3*DivisorSigma[0, n] + 2*DivisorSigma[0, 2*n] + 6*DivisorSigma[1, n] - 3*DivisorSigma[1, 2*n] - 9/2 * DivisorSigma[2, n] + 3/2 * DivisorSigma[2, 2*n], {n, 1, 50}]] (* Vaclav Kotesovec, May 28 2021 *)

STATUS

approved

editing

#17 by Vaclav Kotesovec at Fri May 28 02:19:48 EDT 2021

STATUS

editing

approved

#16 by Vaclav Kotesovec at Fri May 28 02:19:43 EDT 2021

FORMULA

a(n) ~ 3*zeta(3)*n^3/4. - Vaclav Kotesovec, May 28 2021

STATUS

approved

editing

#15 by Bruno Berselli at Thu May 27 17:09:17 EDT 2021

STATUS

reviewed

approved

#14 by Peter Luschny at Thu May 27 17:06:12 EDT 2021

STATUS

proposed

reviewed

#13 by Seiichi Manyama at Thu May 27 12:28:20 EDT 2021

STATUS

editing

proposed