The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A359411 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A359411

a(n) is the number of divisors of n that are both infinitary and exponential.
(history; published version)

#15 by Joerg Arndt at Fri Sep 01 11:26:46 EDT 2023

STATUS

reviewed

approved

#14 by Michel Marcus at Fri Sep 01 10:52:18 EDT 2023

STATUS

proposed

reviewed

#13 by Chai Wah Wu at Fri Sep 01 09:59:03 EDT 2023

STATUS

editing

proposed

#12 by Chai Wah Wu at Fri Sep 01 09:58:07 EDT 2023

PROG

(Python)

from math import prod

from sympy import divisors, factorint

def A359411(n): return prod(sum(1 for d in divisors(e, generator=True) if e|d == e) for e in factorint(n).values()) # Chai Wah Wu, Sep 01 2023

STATUS

approved

editing

#11 by Alois P. Heinz at Sat Dec 31 12:48:42 EST 2022

STATUS

proposed

approved

#10 by Amiram Eldar at Sat Dec 31 06:17:27 EST 2022

STATUS

editing

proposed

#9 by Amiram Eldar at Sat Dec 31 06:17:25 EST 2022

LINKS

Amiram Eldar, <a href="/A359411/b359411.txt">Table of n, a(n) for n = 1..10000</a>

STATUS

approved

editing

#8 by N. J. A. Sloane at Sat Dec 31 01:43:31 EST 2022

STATUS

proposed

approved

#7 by Amiram Eldar at Fri Dec 30 09:15:59 EST 2022

STATUS

editing

proposed

#6 by Amiram Eldar at Fri Dec 30 09:14:50 EST 2022

EXAMPLE

a(8) = 2 since 8 has 2 divisors that are both infinitary and exponential: 2 and 8.