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A270039 a(n) = Smallest m >= 7 containing no threes when represented in any base from 4 through n. 11
8, 9, 10, 32, 32, 36, 64, 64, 64, 64, 64, 64, 64, 100, 100, 100, 100, 100, 100, 100, 100, 100, 104, 145, 145, 145, 145, 145, 145, 145, 145, 145, 145 (list; graph; refs; listen; history; text; internal format)
OFFSET
4,1
COMMENTS
It remains to be determined if the sequence is finite.
LINKS
MAPLE
A270039 := proc(n)
local m, nothree, b;
for m from 7 do
nothree := true;
for b from 4 to n do
convert(convert(m, base, b), set) ;
if 3 in % then
nothree := false;
break;
fi;
end do:
if nothree then
return m;
end if;
end do:
end proc: # R. J. Mathar, Mar 11 2016
MATHEMATICA
Table[SelectFirst[Range[7, 10^3], Total@ Map[Function[k, DigitCount[#, k, 3]], Range[4, n]] == 0 &], {n, 7, 60}] /. n_ /; MissingQ@ n -> Nothing (* Michael De Vlieger, Mar 10 2016, Version 10.2 *)
CROSSREFS
Sequence in context: A343860 A308809 A272142 * A048020 A363760 A048000
KEYWORD
nonn,base,more
AUTHOR
Nathan Fox, Mar 09 2016
STATUS
approved

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Last modified March 1 01:46 EST 2024. Contains 370428 sequences. (Running on oeis4.)