A061657 Numbers k > 1 such that, in base 3, k and k^2 contain the same digits in the same proportion.

184, 196, 464, 500, 544, 550, 552, 584, 588, 622, 626, 670, 706, 1392, 1436, 1472, 1500, 1552, 1632, 1650, 1654, 1656, 1744, 1752, 1764, 1866, 1868, 1878, 1978, 2010, 2030, 2116, 2118, 3922, 4136, 4176, 4308, 4388, 4416, 4500, 4656, 4732, 4756, 4896, 4900

Offset

1,1

Links

Alois P. Heinz, Table of n, a(n) for n = 1..10000

Example

184 = 20211_3 and 184^2 = 1201102221_3.

Maple

p:= n-> add(x^i, i=convert(n, base, 3)):
a:= proc(n) option remember; local k;
      for k from 1+`if`(n=1, 0, a(n-1))
      while p(k)*2<>p(k^2) do od; k
    end:
seq(a(n), n=1..50);  # Alois P. Heinz, May 10 2015

Crossrefs

Cf. A061656, A061658, A061659, A061660, A061661, A061662, A061663, A114258, A061664.

Sequence in context: A272126 A171563 A347504 * A217301 A351278 A239457

Adjacent sequences: A061654 A061655 A061656 * A061658 A061659 A061660

Keyword

base,easy,nonn

Author

Erich Friedman, Jun 16 2001

Extensions

Offset changed to 1 by Alois P. Heinz, May 10 2015

Status

approved