A239011 Exponents m such that the decimal expansion of 6^m exhibits its first zero from the right later than any previous exponent.

0, 2, 3, 4, 6, 7, 8, 12, 17, 24, 29, 42, 44, 101, 104, 128, 1015, 1108, 2629, 9683, 676076, 917474, 34882222, 53229360, 58230015, 90064345, 309000041, 319582553, 342860474, 382090917, 2770253437, 4380407969, 4407585753, 6966554399, 21235488251, 99404304146

Offset: 1

Author

Charles R Greathouse IV and Robert G. Wilson v, Mar 14 2014

Keywords

• nonn
• base

Comments

Assume that a zero precedes all decimal expansions. This will take care of those cases in A030702.

Inspired by the seqfan list discussion Re: "possible sequence", beginning with David Wilson 7:57 PM Mar 06 2014 and continued by M. F. Hasler, Allan C. Wechsler and Franklin T. Adams-Watters.

Crossrefs

Cf. A000400, A030702, A020665, A031142, A239008, A239009, A239010, A239012, A239013, A239014, A239015.

Programs

Mathematica

f[n_] := Position[ Reverse@ Join[{0}, IntegerDigits[ PowerMod[6, n, 10^500]]], 0, 1, 1][[1, 1]]; k = mx = 0; lst = {}; While[k < 10000001, c = f[k]; If[c > mx, mx = c; AppendTo[ lst, k]; Print@ k]; k++]; lst

Extensions

a(27)-a(34) from Bert Dobbelaere, Jan 21 2019

a(35)-a(36) from Chai Wah Wu, Jan 23 2020