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A118736
Number of zeros in binary expansion of 3^n.
0
0, 0, 2, 1, 4, 2, 4, 7, 7, 7, 7, 5, 10, 10, 9, 9, 15, 13, 15, 14, 15, 14, 16, 15, 23, 22, 18, 13, 20, 21, 23, 24, 25, 19, 25, 24, 31, 25, 25, 30, 36, 26, 29, 30, 36, 38, 28, 37, 36, 45, 39, 35, 41, 50, 47, 46, 50, 51, 50, 46, 40, 41, 50, 43, 46, 53, 60, 60, 53, 55, 47, 45, 57, 58
OFFSET
0,3
LINKS
Taylor Dupuy, David E. Weirich, Bits of 3^n in binary, Wieferich primes and a conjecture of Erdős, Journal of Number Theory, Volume 158, January 2016, Pages 268-280.
MATHEMATICA
f[n_] := DigitCount[3^n, 2, 0]; Table[f[n], {n, 0, 73}] (* Ray Chandler, Sep 29 2006 *)
PROG
(PARI) a(n) = #select(x->(x==0), binary(3^n)); \\ Michel Marcus, Apr 14 2020
CROSSREFS
Cf. A011754 (number of ones in binary expansion of 3^n).
Sequence in context: A233521 A035685 A205509 * A201161 A105474 A216568
KEYWORD
base,nonn
AUTHOR
Zak Seidov, May 22 2006
STATUS
approved