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A063620

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

1, 2, 6, 14, 26, 35, 39, 37, 58, 46, 66, 103, 73, 93, 126, 124, 88, 107, 105, 173, 150, 146, 214, 194, 193, 168, 170, 229, 232, 210, 275, 248, 313, 332, 276, 300, 303, 317, 263, 314, 306, 398, 376, 422, 416, 444, 421, 394, 410, 449, 453

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OFFSET

0,2

LINKS

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

MATHEMATICA

a = {}; Do[k = 1; While[ Count[ IntegerDigits[8^k], 4] != n, k++ ]; a = Append[a, k], {n, 0, 50} ]; a

Module[{nn=500, tbl}, tbl=Table[{k, DigitCount[8^k, 10, 4]}, {k, nn}]; Table[SelectFirst[tbl, #[[2]] == n&], {n, 0, 50}]][[;; , 1]] (* Harvey P. Dale, Feb 25 2024 *)

CROSSREFS

Sequence in context: A176752 A140759 A102486 * A162716 A138318 A212964

Adjacent sequences: A063617 A063618 A063619 * A063621 A063622 A063623

KEYWORD

base,nonn

AUTHOR

Robert G. Wilson v, Aug 10 2001

EXTENSIONS

Name corrected by Jon E. Schoenfield, Jun 26 2018

STATUS

approved

URL: https://oeis.org/A063620

⇱ A063620 - OEIS