A025721 Index of 7^n within sequence of numbers of form 3^i*7^j.

1, 3, 7, 13, 21, 30, 41, 54, 69, 85, 103, 123, 145, 169, 194, 221, 250, 281, 313, 347, 383, 421, 460, 501, 544, 589, 636, 684, 734, 786, 840, 895, 952, 1011, 1072, 1134, 1198, 1264, 1332, 1402, 1473, 1546, 1621, 1698, 1776, 1856, 1938, 2022, 2108, 2195, 2284

Offset

1,2

Links

Table of n, a(n) for n=1..51.

Crossrefs

Sequence in context: A299476 A077853 A256588 * A298267 A235532 A195020

Adjacent sequences: A025718 A025719 A025720 * A025722 A025723 A025724

Keyword

nonn

Author

David W. Wilson

Status

approved