A061658 - OEIS

%I #7 Aug 24 2023 14:24:23

%S 45,165,180,657,660,720,882,2165,2193,2331,2625,2628,2640,2880,3362,

%T 3470,3528,3606,3683,3825,8285,8294,8337,8381,8477,8493,8519,8525,

%U 8660,8721,8772,8817,9069,9282,9324,9479,9507,9869,9969,10185,10349,10353,10500,10512

%N Numbers k > 1 such that, in base 4, k and k^2 contain the same digits in the same proportion.

%H Alois P. Heinz, <a href="/A061658/b061658.txt">Table of n, a(n) for n = 1..1000</a>

%e 45 = 231_4 and 45^2 = 133221_4.

%p p:= n-> add(x^i, i=convert(n, base, 4)):

%p a:= proc(n) option remember; local k;

%p       for k from 1+`if`(n=1, 0, a(n-1))

%p       while p(k)*2<>p(k^2) do od; k

%p     end:

%p seq(a(n), n=1..50);  # _Alois P. Heinz_, May 10 2015

%Y Cf. A061656, A061657, A061659, A061660, A061661, A061662, A061663, A114258, A061664.

%K base,easy,nonn

%O 1,1

%A _Erich Friedman_, Jun 16 2001

%E Offset changed to 1 by _Alois P. Heinz_, May 10 2015