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A063603 Smallest k such that 6^k has exactly n 7's in its decimal representation. 0
1, 7, 9, 5, 26, 35, 30, 48, 72, 60, 65, 77, 100, 127, 146, 130, 152, 150, 155, 230, 205, 192, 201, 234, 274, 255, 279, 286, 249, 297, 292, 321, 312, 331, 225, 335, 396, 342, 345, 405, 370, 385, 445, 461, 503, 442, 480, 469, 473, 518, 510 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

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

MATHEMATICA

a = {}; Do[k = 1; While[ Count[ IntegerDigits[6^k], 7] != n, k++ ]; a = Append[a, k], {n, 0, 50} ]; a

Join[{1}, Flatten[With[{p6=6^Range[650]}, Table[First[Position[p6, _?(Count[ IntegerDigits[#], 7]==n&)]], {n, 55}]]]] (* Harvey P. Dale, Oct 03 2011 *)

CROSSREFS

Sequence in context: A215736 A132715 A154910 * A218360 A020788 A198921

Adjacent sequences:  A063600 A063601 A063602 * A063604 A063605 A063606

KEYWORD

base,nonn

AUTHOR

Robert G. Wilson v, Aug 10 2001

EXTENSIONS

Name corrected by Jon E. Schoenfield, Jun 26 2018

STATUS

approved

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Last modified July 23 14:07 EDT 2019. Contains 325254 sequences. (Running on oeis4.)