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%I #12 Jul 23 2023 18:22:46
%S 1,7,9,5,26,35,30,48,72,60,65,77,100,127,146,130,152,150,155,230,205,
%T 192,201,234,274,255,279,286,249,297,292,321,312,331,225,335,396,342,
%U 345,405,370,385,445,461,503,442,480,469,473,518,510
%N Smallest k such that 6^k has exactly n 7's in its decimal representation.
%t a = {}; Do[k = 1; While[ Count[ IntegerDigits[6^k], 7] != n, k++ ]; a = Append[a, k], {n, 0, 50} ]; a
%t Join[{1},Flatten[With[{p6=6^Range[650]},Table[First[Position[p6,_?(Count[ IntegerDigits[#],7]==n&)]],{n,55}]]]] (* _Harvey P. Dale_, Oct 03 2011 *)
%K base,nonn
%O 0,2
%A _Robert G. Wilson v_, Aug 10 2001
%E Name corrected by _Jon E. Schoenfield_, Jun 26 2018
%E Offset corrected by _Sean A. Irvine_, Jul 23 2023
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