A063583 Smallest k such that 4^k has exactly n 8's in its decimal representation.

1, 7, 13, 31, 27, 41, 65, 37, 89, 110, 90, 117, 135, 158, 155, 201, 171, 211, 208, 175, 161, 235, 227, 213, 290, 321, 316, 354, 363, 344, 459, 277, 532, 350, 517, 409, 448, 419, 536, 465, 541, 490, 525, 549, 565, 605, 604, 674, 577, 719, 615

Offset

0,2

Links

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

Mathematica

a = {}; Do[k = 1; While[ Count[ IntegerDigits[4^k], 8] != n, k++ ]; a = Append[a, k], {n, 0, 50} ]; a
With[{tbl=Table[{n, DigitCount[4^n, 10, 8]}, {n, 1000}]}, Table[SelectFirst[tbl, #[[2]]==k&], {k, 0, 50}]][[;; , 1]] (* Harvey P. Dale, Oct 24 2023 *)

Crossrefs

Sequence in context: A133325 A336117 A283709 * A350072 A065764 A273757

Adjacent sequences: A063580 A063581 A063582 * A063584 A063585 A063586

Keyword

base,nonn

Author

Robert G. Wilson v, Aug 10 2001

Extensions

Name corrected by Jon E. Schoenfield, Jun 26 2018

Status

approved