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A342503 Numbers k such that k divides A340740(k). 0
1, 2, 3, 4, 6, 19, 48, 111, 4630, 5428, 13569, 41628, 87659, 108990, 555716, 751863, 973813, 5124585, 8663699 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..19.

EXAMPLE

a(8) = 111 is a term because 111 divides A340740(111) = 444.

MAPLE

filter:= proc(n) local k; add(`if`(igcd(k, n)=1, (n-k) mod k, 0), k=1..n/2) mod n = 0 end proc:

select(filter, [$1..10^5]);

PROG

(Python)

from math import gcd

A342503_list = [k for k in range(1, 10**4) if sum(k % i for i in range(1, k//2+1) if gcd(i, k) == 1) % k == 0] # Chai Wah Wu, Mar 18 2021

CROSSREFS

Cf. A340740.

Sequence in context: A084391 A259383 A220702 * A217351 A274238 A115035

Adjacent sequences:  A342500 A342501 A342502 * A342504 A342505 A342506

KEYWORD

nonn,more

AUTHOR

J. M. Bergot and Robert Israel, Mar 16 2021

EXTENSIONS

a(14)-a(17) from Chai Wah Wu, Mar 18 2021

a(18)-a(19) from Martin Ehrenstein, May 14 2021

STATUS

approved

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Last modified December 6 11:48 EST 2021. Contains 349563 sequences. (Running on oeis4.)