OFFSET
1,2
COMMENTS
Assume that a zero precedes all decimal expansions. This will take care of those cases in A030703.
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.
MATHEMATICA
f[n_] := Position[ Reverse@ Join[{0}, IntegerDigits[ PowerMod[7, n, 10^500]]], 0, 1, 1][[1, 1]]; k = mx = 0; lst = {}; While[k < 500000001, c = f[k]; If[c > mx, mx = c; AppendTo[ lst, k]; Print@ k]; k++]; lst
CROSSREFS
KEYWORD
nonn,base,more
AUTHOR
Charles R Greathouse IV and Robert G. Wilson v, Mar 14 2014
EXTENSIONS
a(19)-a(22) from Bert Dobbelaere, Jan 21 2019
a(23)-a(25) from Chai Wah Wu, Jan 15 2020
STATUS
approved