OFFSET
1,1
COMMENTS
Smallest k such that sopfr(k) = n*q^2.
a(n) = A213386(n), except for n = 1, 105, 173, 213, 227, 287, …
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
a(105) = 3764 because 3764 = 2^2 * 941 and the sum of prime factors (counted with multiplicity) is 4 + 941 = 945 = 105*9 where 9 is a square.
MAPLE
with(numtheory):
sopfr:= proc(n) option remember;
add(i[1]*i[2], i=ifactors(n)[2])
end:
a:= proc(n) local k, p;
for k from 2 while irem(sopfr(k), n, 'p')>0 or
sqrt(p)<>floor(sqrt(p)) or p=1 do od; k
end:
seq (a(n), n=1..100);
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Lagneau, Jun 11 2012
STATUS
approved