OFFSET
1,1
COMMENTS
Subsequence of A120944.
LINKS
Donovan Johnson, Table of n, a(n) for n = 1..500
EXAMPLE
Prime factors of 19019 are 7, 11, 13 and 19 while d(19019) = 16. We have that 19019 + 16 = 19035 and 19035 / (7 - 16) = -2115, 19035 / (11 - 16) = -3807, 19035 / (13 - 16) = -6345 and 19035 / (19 - 16) = 6345.
MAPLE
with (numtheory); P:=proc(q) local 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 or a[i][1]=tau(n) then ok:=0; break;
else if not type((n+tau(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(10^6);
CROSSREFS
KEYWORD
nonn
AUTHOR
Paolo P. Lava, Aug 20 2013
EXTENSIONS
First term deleted by Paolo P. Lava, Sep 23 2013
STATUS
approved