A065335 3-exponents to represent 3-smooth numbers (A065332).

0, 0, 1, 0, 0, 1, 0, 0, 2, 0, 0, 1, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset

1,9

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

a(n) = A007949(n) * A065333(n).

a(n) = log_3(n / A006519(n)), where log_3 = A062153. For k > 0 with A065332(k) > 0: A065332(k) = (2^A065334(k)) * (3^a(k)).

Mathematica

a[n_] := If[n/2^IntegerExponent[n, 2]/3^(e = IntegerExponent[n, 3]) == 1, e, 0]; Array[a, 100] (* Amiram Eldar, Feb 21 2021 *)

Crossrefs

Cf. A006519, A007949, A062153, A065332, A065333, A065334.

Sequence in context: A092575 A365800 A308264 * A230264 A374208 A363127

Adjacent sequences: A065332 A065333 A065334 * A065336 A065337 A065338

Keyword

nonn

Author

Reinhard Zumkeller, Oct 29 2001

Status

approved