OFFSET
1,2
COMMENTS
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Paolo P. Lava)
EXAMPLE
k = a(18) = 196 of which divisor power sums for k=0,1,2,3,4 are 9,399,51471, 8613489, 1574446419. sigma_1(k) = 399 and sigma_4(k) = 51471*30589=399*129*30589. Thus both sigma_2(k) and sigma_1(k) divide sigma_4(k).
MATHEMATICA
Select[Range[1300], Divisible @@ DivisorSigma[{4, 1}, #] &] (* Amiram Eldar, Jun 15 2024 *)
PROG
(PARI) is(k) = {my(f = factor(k)); !(sigma(f, 4) % sigma(f)); } \\ Amiram Eldar, Jun 15 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved