A063607 Smallest k such that 7^k has exactly n 1's in its decimal representation.

1, 4, 6, 12, 19, 34, 24, 37, 38, 57, 52, 92, 96, 88, 116, 142, 133, 156, 108, 147, 115, 158, 209, 190, 180, 266, 200, 270, 240, 262, 263, 208, 279, 366, 339, 304, 352, 331, 406, 316, 407, 385, 396, 434, 437, 376, 386, 414, 470, 450, 551

Offset

0,2

Links

Table of n, a(n) for n=0..50.

Mathematica

a = {}; Do[k = 1; While[ Count[ IntegerDigits[7^k], 1] != n, k++ ]; a = Append[a, k], {n, 0, 50} ]; a
Table[Position[DigitCount[7^Range[600], 10, 1], n, 1, 1], {n, 0, 50}]//Flatten (* Harvey P. Dale, Jan 12 2019 *)

Crossrefs

Sequence in context: A048641 A023599 A087881 * A306270 A045956 A057339

Adjacent sequences: A063604 A063605 A063606 * A063608 A063609 A063610

Keyword

base,nonn

Author

Robert G. Wilson v, Aug 10 2001

Extensions

Name corrected by Jon E. Schoenfield, Jun 26 2018

Status

approved