OFFSET
1,1
COMMENTS
a(15) > 10^11. - Giovanni Resta, Sep 20 2013
Subsequence of A120944.
EXAMPLE
Prime factors of 82218 are 2, 3, 71, 193 and tau(82218) = 16, phi(82218) = 26680. 82218 + 26680 = 109098 and 109098 / (2 + 16) = 6061, 109098 / (3 + 16) = 5742, 109098 / (71 + 16) = 1254, 109098 / (193 + 16) = 522.
MAPLE
with (numtheory); P:=proc(q) global a, b, c, i, ok, p, n;
for n from 2 to q do if not isprime(n) then a:=ifactors(n)[2]; ok:=1;
for i from 1 to nops(a) do if a[i][2]>1 then ok:=0; break;
else if not type((n+phi(n))/(a[i][1]+tau(n)), integer) then ok:=0; break; fi; fi; od; if ok=1 then print(n); fi; fi; od; end: P(6*10^9);
CROSSREFS
KEYWORD
nonn
AUTHOR
Paolo P. Lava, Sep 20 2013
EXTENSIONS
a(4)-a(14) from Giovanni Resta, Sep 20 2013
First term deleted by Paolo P. Lava, Sep 23 2013
STATUS
approved