The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A258600 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A258600

a(n) is the index m such that A036966(m) = prime(n)^3.
(history; published version)

#20 by N. J. A. Sloane at Wed Sep 11 00:32:48 EDT 2024

STATUS

proposed

approved

#19 by Chai Wah Wu at Tue Sep 10 23:36:24 EDT 2024

STATUS

editing

proposed

#18 by Chai Wah Wu at Tue Sep 10 23:36:19 EDT 2024

PROG

return c # Chai Wah Wu, Sep 10 2024

#17 by Chai Wah Wu at Tue Sep 10 23:36:03 EDT 2024

PROG

(Python)

from math import gcd

from sympy import prime, integer_nthroot, factorint

def A258600(n):

c, m = 0, prime(n)**3

for w in range(1, integer_nthroot(m, 5)[0]+1):

if all(d<=1 for d in factorint(w).values()):

for y in range(1, integer_nthroot(z:=m//w**5, 4)[0]+1):

if gcd(w, y)==1 and all(d<=1 for d in factorint(y).values()):

c += integer_nthroot(z//y**4, 3)[0]

return c # Chai Wah Wu, Sep 10 2024

STATUS

approved

editing

#16 by OEIS Server at Tue Feb 07 05:57:28 EST 2023

LINKS

Amiram Eldar, <a href="/A258600/b258600_1.txt">Table of n, a(n) for n = 1..1000</a>

#15 by Joerg Arndt at Tue Feb 07 05:57:28 EST 2023

STATUS

reviewed

approved

Discussion

Tue Feb 07

05:57

OEIS Server: Installed new b-file as b258600.txt.  Old b-file is now b258600_1.txt.

#14 by Michel Marcus at Tue Feb 07 02:07:02 EST 2023

STATUS

proposed

reviewed

#13 by Amiram Eldar at Tue Feb 07 01:27:18 EST 2023

STATUS

editing

proposed

Discussion

Tue Feb 07

02:07

Michel Marcus: yes

#12 by Amiram Eldar at Tue Feb 07 01:11:57 EST 2023

FORMULA

Also the index smallest number m such that A258568(m) = prime(n):

#11 by Amiram Eldar at Tue Feb 07 01:10:58 EST 2023

FORMULA

Also smallest number the index m such that A258568(m) = prime(n):