0,9
a(n) = A077267(A000079(n));
a(A104321(n))=n and a(m)<>n for m < A104321(n);
N. J. A. Sloane conjectures a(n)>0 for n>15, see A102483.
Table of n, a(n) for n=0..87.
n=13: 2^13=8192 -> '102020102', a(13) = 4.
Table[DigitCount[2^n, 3, 0], {n, 0, 90}] (* Harvey P. Dale, May 06 2014 *)
Cf. A004642, A007089.
Sequence in context: A140751 A259922 A162741 * A242618 A180264 A225200
Adjacent sequences: A104317 A104318 A104319 * A104321 A104322 A104323
nonn
Reinhard Zumkeller, Mar 01 2005
approved