A112760 Exponent of 2 (value of i) in n-th number of the form 2^i*3^j*5^k.

0, 1, 0, 2, 0, 1, 3, 0, 1, 2, 0, 4, 1, 2, 3, 0, 0, 1, 5, 2, 3, 0, 4, 1, 1, 2, 6, 3, 0, 4, 0, 1, 5, 2, 2, 3, 0, 7, 0, 4, 1, 5, 1, 2, 6, 3, 3, 0, 4, 0, 1, 8, 1, 5, 2, 6, 2, 3, 0, 7, 4, 0, 4, 1, 5, 1, 2, 9, 2, 6, 3, 0, 7, 3, 0, 4, 0, 1, 8, 5, 1, 5, 2, 6, 2, 3, 10, 3, 0, 7, 4, 0, 1, 8, 4, 1, 5, 1, 2, 9, 6, 2, 6, 3, 0

Offset: 1

Author

Reinhard Zumkeller, Sep 18 2005

Keywords

• nonn

Links

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

Crossrefs

Cf. A007814, A022328, A051037, A112759, A112761, A112762.

Programs

Mathematica

IntegerExponent[#, 2] & /@ Select[Range[3000], Last @ Map[First, FactorInteger[#]] <= 5 &] (* Amiram Eldar, Feb 07 2020 *)

Formula

a(n) = A007814(A051037(n));

a(n) = A112759(n) - A112761(n) - A112762(n).