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A104320 Number of zeros in ternary representation of 2^n. 8
0, 0, 0, 0, 0, 1, 1, 1, 2, 2, 1, 1, 1, 4, 1, 0, 4, 2, 3, 3, 3, 3, 3, 7, 7, 9, 5, 6, 6, 4, 4, 3, 5, 6, 7, 9, 9, 10, 6, 6, 9, 9, 8, 9, 8, 7, 13, 12, 13, 9, 5, 9, 8, 6, 16, 13, 9, 10, 11, 11, 7, 14, 13, 13, 9, 12, 14, 15, 15, 11, 11, 17, 15, 19, 14, 19, 12, 18, 15, 11, 10, 16, 15, 14, 14, 13, 17, 14 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,9
COMMENTS
Conjecture from N. J. A. Sloane: a(n) > 0 for n > 15, see A102483.
LINKS
FORMULA
a(n) = A077267(A000079(n)).
a(A104321(n))=n and a(m)<>n for m < A104321(n).
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
(Magma) [Multiplicity(Intseq(2^n, 3), 0):n in [0..90]]; // Marius A. Burtea, Nov 17 2019
CROSSREFS
Sequence in context: A259922 A162741 A340145 * A350818 A340142 A242618
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, Mar 01 2005
STATUS
approved

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Last modified March 3 04:18 EST 2024. Contains 370499 sequences. (Running on oeis4.)