OFFSET
1,1
COMMENTS
a(39) > 5*10^13. - Hiroaki Yamanouchi, Aug 27 2015
LINKS
Hiroaki Yamanouchi, Table of n, a(n) for n = 1..38
EXAMPLE
Arithmetic derivative of 50000 is 150000.
MAPLE
with(numtheory): P:=proc(q) local a, b, n, p;
for n from 1 to q do a:=n*add(op(2, p)/op(1, p), p=ifactors(n)[2]);
if a>n then b:=ilog10(n)+1;
if n=(a mod 10^b) then print(n); fi;
fi; od; end: P(10^9);
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Paolo P. Lava, Oct 31 2014
EXTENSIONS
a(10)-a(23) from Hiroaki Yamanouchi, Aug 27 2015
STATUS
approved