A249540 Digits of n' end in n, where n' is the arithmetic derivative of n.

50000, 87500, 600000, 987500, 4782272, 24800000, 45600000, 85650000, 95200000, 962650000, 999987500, 2999062272, 4285650000, 7500000000, 9977650000, 9999987500, 23076922368, 74837600000, 80000000000, 85479410112, 90000000000, 280000000000, 480000000000

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

Cf. A003415.

Sequence in context: A159233 A145538 A106773 * A271115 A269475 A160932

Adjacent sequences: A249537 A249538 A249539 * A249541 A249542 A249543

Keyword

nonn,base

Author

Paolo P. Lava, Oct 31 2014

Extensions

a(10)-a(23) from Hiroaki Yamanouchi, Aug 27 2015

Status

approved