OFFSET
1,1
COMMENTS
Mainly primes.
EXAMPLE
If n = 16138, starting from the least significant digit, let us cut the number into the set {8, 38, 138, 6138}. We have:
8’ = 12;
38’ = 21;
138’ = 121;
6138’ = 7917.
Finally, 12 + 21 + 121 + 7917 = 16138’ = 8071.
MAPLE
with(numtheory); P:=proc(q) local a, c, k, n, p;
for n from 10 to q do
a:=0; k:=1; while (n mod 10^k)<n do c:=(n mod 10^k);
a:=a+c*add(op(2, p)/op(1, p), p=ifactors(c)[2]); k:=k+1; od;
if a=n*add(op(2, p)/op(1, p), p=ifactors(n)[2]) then print(n);
fi; od; end: P(10^10);
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Paolo P. Lava, Jun 19 2014
STATUS
approved