A086414 Minimal exponent in prime factorization of 3-smooth numbers.

0, 1, 1, 2, 1, 3, 2, 1, 4, 1, 1, 3, 5, 2, 1, 1, 6, 2, 4, 1, 2, 7, 2, 1, 1, 3, 5, 8, 2, 2, 1, 3, 1, 9, 2, 3, 6, 1, 3, 2, 10, 2, 4, 1, 1, 3, 3, 11, 7, 2, 4, 2, 1, 3, 4, 12, 1, 2, 4, 3, 1, 8, 3, 5, 13, 2, 2, 4, 4, 1, 1, 3, 5, 14, 3, 2, 9, 4, 5, 1, 2, 3, 5, 15, 4, 2, 1, 4, 6, 1, 3, 3, 10, 5, 16, 5, 2, 2

Offset

1,4

Links

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

Formula

a(n) = A051904(A003586(n));

a(n) <= A086415(n) <= A069352(n).

Mathematica

s = {}; m = 12; Do[n = 3^k; While[n <= 3^m, AppendTo[s, n]; n*=2], {k, 0, m}]; maxExp[1] = 0; maxExp[n_] := Min @@ Last /@ FactorInteger[n]; maxExp /@ Union[s] (* Amiram Eldar, Jan 29 2020 *)

Crossrefs

Cf. A003586, A051904, A069352, A086415.

Sequence in context: A329515 A169742 A257077 * A098896 A108371 A138530

Adjacent sequences: A086411 A086412 A086413 * A086415 A086416 A086417

Keyword

nonn

Author

Reinhard Zumkeller, Jul 18 2003

Status

approved