A025720 Index of 7^n within sequence of numbers of form 2^i*7^j.

1, 4, 10, 19, 31, 46, 63, 83, 106, 132, 161, 192, 226, 263, 303, 346, 391, 439, 490, 544, 601, 660, 722, 787, 855, 926, 999, 1075, 1154, 1236, 1321, 1409, 1499, 1592, 1688, 1787, 1889, 1993, 2100, 2210, 2323, 2439, 2557, 2678, 2802, 2929, 3059, 3191, 3326

Offset

1,2

Links

Table of n, a(n) for n=1..49.

Crossrefs

Sequence in context: A160425 A152946 A162505 * A022793 A005448 A373699

Adjacent sequences: A025717 A025718 A025719 * A025721 A025722 A025723

Keyword

nonn

Author

David W. Wilson

Status

approved