OFFSET
0,9
COMMENTS
Conjecture from N. J. A. Sloane: a(n) > 0 for n > 15, see A102483.
LINKS
Robert Israel, Table of n, a(n) for n = 0..10000
EXAMPLE
n=13: 2^13=8192 -> '102020102', a(13) = 4.
MAPLE
f:= n -> numboccur(0, convert(2^n, base, 3)):
map(f, [$0..100]); # Robert Israel, Nov 17 2019
MATHEMATICA
Table[DigitCount[2^n, 3, 0], {n, 0, 90}] (* Harvey P. Dale, May 06 2014 *)
PROG
(PARI) a(n) = my(d=vecsort(digits(2^n, 3))); #setintersect(d, vector(#d)) \\ Felix Fröhlich, Nov 17 2019
(PARI) a(n) = #select(d->!d, digits(2^n, 3)); \\ Ruud H.G. van Tol, May 09 2024
(Magma) [Multiplicity(Intseq(2^n, 3), 0):n in [0..90]]; // Marius A. Burtea, Nov 17 2019
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, Mar 01 2005
STATUS
approved