A025675 Exponent of 8 (value of j) in n-th number of form 7^i*8^j.

0, 0, 1, 0, 1, 2, 0, 1, 2, 3, 0, 1, 2, 3, 4, 0, 1, 2, 3, 4, 5, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6, 7, 8, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11

Offset

1,6

Links

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

Formula

a(n) = A244413(A036566(n)). - Amiram Eldar, Nov 08 2025

Mathematica

seq[lim_] := IntegerExponent[Flatten[Table[7^i*8^j, {i, 0, Log[7, lim]}, {j, 0, Log[8, lim/7^i]}]] // Sort, 8]; seq[10^12] (* Amiram Eldar, Nov 08 2025 *)

Crossrefs

Cf. A025669, A036566, A244413.

Differs from A002262 at a(136).

Sequence in context: A025668 A373748 A048151 * A025682 A025691 A002262

Adjacent sequences: A025672 A025673 A025674 * A025676 A025677 A025678

Keyword

nonn,easy

Author

David W. Wilson

Status

approved