OFFSET
1,2
EXAMPLE
10 is in the sequence because the prime factorization of 10^4+1=10001 is 73*137 and 73+137=210 is divisible by 10.
MAPLE
filter:= proc(n) local F, t, y;
F:= ifactors(n^4+1)[2];
y:= add(t[1]*t[2], t=F);
y mod n = 0
end proc:
select(filter, [$1..200000]);
CROSSREFS
KEYWORD
nonn,more
AUTHOR
J. M. Bergot and Robert Israel, Aug 07 2019
STATUS
approved