The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A066859 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A066859

Product of sums of divisors and non-divisors.
(history; published version)

#20 by Alois P. Heinz at Fri Feb 05 07:27:01 EST 2021

COMMENTS

The related 'Sums of sums of divisors and non-divisors' is in OEIS via A000203(n) + A024816(n) = A000217(n).

A000203(n) + A024816(n) = A000217(n).

STATUS

editing

approved

#19 by Alois P. Heinz at Fri Feb 05 07:26:56 EST 2021

STATUS

proposed

editing

#18 by David A. Corneth at Fri Feb 05 07:20:42 EST 2021

STATUS

editing

proposed

Discussion

Fri Feb 05

07:26

Alois P. Heinz: ... rejected ...

#17 by David A. Corneth at Fri Feb 05 07:20:23 EST 2021

COMMENTS

The related 'Sums of sums of divisors and non-divisors' is in OEIS via A000203(n) + A024816(n) = A000217(n).

STATUS

approved

editing

Discussion

Fri Feb 05

07:20

David A. Corneth: Sorry for reopening so fast. Made the change discussed in pink boxes.

#16 by Alois P. Heinz at Fri Feb 05 07:10:47 EST 2021

STATUS

proposed

approved

#15 by David A. Corneth at Fri Feb 05 06:17:21 EST 2021

STATUS

editing

proposed

Discussion

Fri Feb 05

06:39

Amiram Eldar: The comment is here to say that the analogous sequence, with sum instead of product, is "Sum of sums of divisors and non-divisors" is already in the OEIS, it is the sequence of triangular numbers A000217(n).
So for me it is a good comment.

06:50

David A. Corneth: I see. Would it make sense to say something like "the related 'Sums of sumos of divisors and non-divisors' is in OEIS via 	
A000203(n) + A024816(n) = A000217(n)."?

07:11

Amiram Eldar: Yes, I think that it can be improved like you say.

#14 by David A. Corneth at Fri Feb 05 06:16:52 EST 2021

LINKS

David A. Corneth, <a href="/A066859/b066859.txt">Table of n, a(n) for n = 1..10000</a>

STATUS

approved

editing

Discussion

Fri Feb 05

06:17

David A. Corneth: Do we really need the comment? It's a formula that doesn't use this sequence.

#13 by Alois P. Heinz at Fri Feb 05 05:49:18 EST 2021

STATUS

editing

approved

#12 by Alois P. Heinz at Fri Feb 05 05:49:16 EST 2021

MAPLE

a:= n-> (s-> s*(n*(n+1)/2-s))(numtheory[sigma](n)):

seq(a(n), n=1..45); # Alois P. Heinz, Feb 05 2021

#11 by Alois P. Heinz at Fri Feb 05 05:48:51 EST 2021

DATA

0, 0, 8, 21, 54, 108, 160, 315, 416, 666, 648, 1400, 1078, 1944, 2304, 3255, 2430, 5148, 3400, 7056, 6368, 7812, 6048, 14400, 9114, 12978, 13520, 19600, 12150, 28296, 14848, 29295, 24624, 29214, 27936, 52325, 25270, 40860, 40544, 65700, 34398, 77472, 39688

STATUS

approved

editing