The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A053150 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A053150

Cube root of largest cube dividing n.
(history; published version)

#48 by Susanna Cuyler at Fri Aug 20 09:01:57 EDT 2021

STATUS

proposed

approved

#47 by Ilya Gutkovskiy at Fri Aug 20 06:38:19 EDT 2021

STATUS

editing

proposed

#46 by Ilya Gutkovskiy at Fri Aug 20 06:25:14 EDT 2021

FORMULA

G.f.: Sum_{k>=1} phi(k) * x^(k^3) / (1 - x^(k^3)). - Ilya Gutkovskiy, Aug 20 2021

STATUS

approved

editing

#45 by Alois P. Heinz at Thu Aug 19 06:30:31 EDT 2021

STATUS

proposed

approved

#44 by Chai Wah Wu at Wed Aug 18 15:08:56 EDT 2021

STATUS

editing

proposed

#43 by Chai Wah Wu at Wed Aug 18 15:08:53 EDT 2021

PROG

(Python 3.8+)

from math import prod

from sympy import factorint

def A053150(n): return prod(p**(q//3) for p, q in factorint(n).items()) # Chai Wah Wu, Aug 18 2021

STATUS

approved

editing

#42 by Michel Marcus at Thu Dec 31 02:26:17 EST 2020

STATUS

reviewed

approved

#41 by Joerg Arndt at Thu Dec 31 02:23:25 EST 2020

STATUS

proposed

reviewed

Discussion

Thu Dec 31

02:26

Michel Marcus: yes

#40 by Ridouane Oudra at Wed Dec 30 14:09:05 EST 2020

STATUS

editing

proposed

#39 by Ridouane Oudra at Wed Dec 30 14:08:14 EST 2020

FORMULA

a(n) = Sum_{d^3|n} phi(d). - Ridouane Oudra, Dec 30 2020

STATUS

approved

editing