A025641 Exponent of 3 (value of i) in n-th number of form 3^i*6^j.

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

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Comments

Also known as (exponent of 3 in n-th number of the form 3^i * 6^j) - (exponent of 2 in n-th number of the form 3^i * 6^j). - David A. Corneth, Jan 12 2021

Examples

			a(5) = 1 as the 5th number of the form 3^i * 6^j is 18 = 3^1 * 6^1 which has exponent of 3 equal to 1. - _David A. Corneth_, Jan 12 2021
		

Links

• David A. Corneth, Table of n, a(n) for n = 1..10000

Crossrefs

Differs from A025649 at a(114). A025657 is exponent of 6.

Cf. A025614.

Programs

Mathematica

SortBy[Join @@ Table[{i, 3^i*6^j}, {i, 0, Log[3, #]}, {j, 0, Log[6, #/3^i]}], Last] &[10^8][[All, 1]] (* Michael De Vlieger, Jan 12 2021, after Amiram Eldar at A025614 *)