A025688 Exponent of 10 (value of j) in n-th number of form 6^i*10^j.

0, 0, 1, 0, 1, 2, 0, 1, 2, 3, 0, 1, 2, 3, 0, 4, 1, 2, 3, 0, 4, 1, 5, 2, 3, 0, 4, 1, 5, 2, 6, 3, 0, 4, 1, 5, 2, 6, 3, 7, 0, 4, 1, 5, 2, 6, 3, 7, 0, 4, 8, 1, 5, 2, 6, 3, 7, 0, 4, 8, 1, 5, 9, 2, 6, 3, 7, 0, 4, 8, 1, 5, 9, 2, 6, 10, 3, 7, 0, 4, 8, 1, 5, 9, 2, 6, 10, 3, 7, 0, 11, 4, 8, 1, 5, 9, 2, 6, 10, 3, 7, 0, 11, 4, 8

Offset

1,6

Links

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

Formula

a(n) = A122840(A025629(n)). - Amiram Eldar, Nov 09 2025

Mathematica

seq[lim_] := IntegerExponent[Flatten[Table[6^i*10^j, {i, 0, Log[6, lim]}, {j, 0, Log10[lim/6^i]}]] // Sort, 10]; seq[10^12] (* Amiram Eldar, Nov 09 2025 *)

Crossrefs

Cf. A025629, A025663, A122840.

Sequence in context: A385237 A025658 A025673 * A025645 A233381 A025680

Adjacent sequences: A025685 A025686 A025687 * A025689 A025690 A025691

Keyword

nonn,easy

Author

David W. Wilson

Status

approved