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A239010 Exponents m such that the decimal expansion of 5^m exhibits its first zero from the right later than any previous exponent. 7
0, 2, 3, 5, 6, 9, 11, 15, 17, 18, 25, 26, 30, 33, 57, 58, 153, 1839, 3290, 4081, 16431, 577839, 2190974, 15167023, 23155442, 24477994, 36290003, 53687441, 62497567, 181850218, 790111167, 872257561, 4531889178, 26964400609, 32626158305, 268600630073 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Assume that a zero precedes all decimal expansions. This will take care of those cases in A008839.

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.

Highest position known is 232th digit from the right for a(33). - Bert Dobbelaere, Jan 21 2019

LINKS

Table of n, a(n) for n=1..36.

MATHEMATICA

f[n_] := Position[ Reverse@ Join[{0}, IntegerDigits[ PowerMod[5, n, 10^500]]], 0, 1, 1][[1, 1]]; k = mx = 0; lst = {}; While[k < 100000001, c = f[k]; If[c > mx, mx = c; AppendTo[ lst, k]; Print@ k]; k++]; lst

CROSSREFS

Cf. A000351, A008839, A020665, A031142, A239008, A239009, A239011, A239012, A239013, A239014, A239015.

Sequence in context: A327516 A054639 A123399 * A104738 A319469 A325863

Adjacent sequences:  A239007 A239008 A239009 * A239011 A239012 A239013

KEYWORD

nonn,base

AUTHOR

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

EXTENSIONS

a(30)-a(33) from Bert Dobbelaere, Jan 21 2019

a(34)-a(36) from Chai Wah Wu, Jan 18 2020

STATUS

approved

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Last modified July 4 11:58 EDT 2020. Contains 335448 sequences. (Running on oeis4.)