login
A342649
Numbers k such that A238525(k) divides k.
1
6, 8, 9, 18, 20, 21, 24, 25, 32, 36, 42, 45, 48, 49, 50, 52, 56, 64, 66, 78, 80, 81, 98, 100, 108, 110, 112, 117, 120, 121, 125, 126, 128, 130, 132, 135, 144, 152, 154, 160, 168, 169, 170, 175, 186, 192, 200, 204, 210, 216, 225, 234, 242, 243, 252, 255, 264, 266, 276, 280, 285, 289, 290, 301, 306
OFFSET
1,1
COMMENTS
Includes squares of odd primes.
LINKS
EXAMPLE
a(4) = 18 is a term because A238525(18) = 2 divides 18.
MAPLE
filter:= proc(n) local t, s, r;
if isprime(n) then return false fi;
s:= add(t[1]*t[2], t=ifactors(n)[2]);
r:= n mod s;
r <> 0 and n mod r = 0;
end proc:
select(filter, [$4..1000]);
CROSSREFS
Cf. A238525.
Disjoint from A036844.
Sequence in context: A092115 A083966 A074326 * A254321 A174213 A284990
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Mar 17 2021
STATUS
approved