The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A061503 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A061503

a(n) = Sum_{k=1..n} tau(k^2), where tau is the number of divisors function A000005.
(history; published version)

#60 by Alois P. Heinz at Tue May 10 17:05:33 EDT 2022

STATUS

proposed

approved

#59 by Chai Wah Wu at Tue May 10 17:02:30 EDT 2022

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editing

proposed

#58 by Chai Wah Wu at Tue May 10 17:02:26 EDT 2022

PROG

(Python)

from math import prod

from sympy import factorint

def A061503(n): return sum(prod(2*e+1 for e in factorint(k).values()) for k in range(1, n+1)) # Chai Wah Wu, May 10 2022

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approved

editing

#57 by Vaclav Kotesovec at Mon Dec 28 07:15:30 EST 2020

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editing

approved

#56 by Vaclav Kotesovec at Mon Dec 28 07:15:18 EST 2020

LINKS

Steven R. Finch, <a href="http://arxiv.org/abs/2001.00578">Errata and Addenda to Mathematical Constants</a>, p. 19.

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approved

editing

#55 by Michel Marcus at Mon Sep 02 02:19:41 EDT 2019

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reviewed

approved

#54 by Joerg Arndt at Mon Sep 02 02:07:55 EDT 2019

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proposed

reviewed

#53 by Joerg Arndt at Mon Sep 02 02:07:50 EDT 2019

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editing

proposed

#52 by Joerg Arndt at Mon Sep 02 02:07:47 EDT 2019

COMMENTS

Also, a(n) is the number of pairs of positive integers <= n with their LCM <= n. - Andrew Howroyd, Sep 01 2019

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proposed

editing

#51 by Michel Marcus at Mon Sep 02 00:51:05 EDT 2019

STATUS

editing

proposed