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Revision History for A339689

(Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A339689

a(n) = Sum_{d|n} 9^(d-1).
(history; published version)

#18 by Joerg Arndt at Wed Jun 26 02:05:59 EDT 2024

STATUS

reviewed

approved

#17 by Michel Marcus at Wed Jun 26 00:57:31 EDT 2024

STATUS

proposed

reviewed

#16 by G. C. Greubel at Tue Jun 25 21:07:15 EDT 2024

STATUS

editing

proposed

#15 by G. C. Greubel at Tue Jun 25 21:07:11 EDT 2024

PROG

(Magma)

A339689:= func< n | (&+[9^(d-1): d in Divisors(n)]) >;

[A339689(n): n in [1..40]]; // G. C. Greubel, Jun 25 2024

(SageMath)

def A339689(n): return sum(9^(k-1) for k in (1..n) if (k).divides(n))

[A339689(n) for n in range(1, 41)] # G. C. Greubel, Jun 25 2024

CROSSREFS

Cf. A001019, A320074.

Cf. A001019, Sums of the form Sum_{d|n} q^(d-1): A034729, (q=2), A034730, (q=3), A113999, A320074, (q=10), A339684, (q=4), A339685, (q=5), A339686, (q=6), A339687, (q=7), A339688 (q=8), this sequence (q=9).

STATUS

approved

editing

#14 by Vaclav Kotesovec at Sat Jun 05 06:25:36 EDT 2021

STATUS

editing

approved

#13 by Vaclav Kotesovec at Sat Jun 05 06:25:33 EDT 2021

FORMULA

a(n) ~ 9^(n-1). - Vaclav Kotesovec, Jun 05 2021

STATUS

approved

editing

#12 by Joerg Arndt at Mon Dec 14 10:29:06 EST 2020

STATUS

reviewed

approved

#11 by Michel Marcus at Mon Dec 14 09:39:59 EST 2020

STATUS

proposed

reviewed

#10 by Seiichi Manyama at Mon Dec 14 07:05:16 EST 2020

STATUS

editing

proposed

#9 by Seiichi Manyama at Mon Dec 14 07:00:53 EST 2020

LINKS

Seiichi Manyama, <a href="/A339689/b339689.txt">Table of n, a(n) for n = 1..1000</a>