OFFSET
1,1
COMMENTS
3907 occurs twice, as a(25) and a(28). Are there any others?
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
f:= proc(n) local t, k;
t:= add(`if`(igcd(n, k)=1, n mod k, 0), k=2..n-1);
if isprime(t) then t fi
end proc:
map(f, [$1..1000]);
CROSSREFS
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Jan 18 2021
STATUS
approved