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A188341 Numbers having no 0's and not more than one 1 in their representation in base 3. 8
1, 2, 5, 7, 8, 17, 23, 25, 26, 53, 71, 77, 79, 80, 161, 215, 233, 239, 241, 242, 485, 647, 701, 719, 725, 727, 728, 1457, 1943, 2105, 2159, 2177, 2183, 2185, 2186, 4373, 5831, 6317, 6479, 6533, 6551, 6557, 6559, 6560, 13121, 17495, 18953 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..1000

V. Shevelev, Binomial Coefficient Predictors, Journal of Integer Sequences, Vol. 14 (2011), Article 11.2.8

MAPLE

a:= proc(n) option remember; local i, l, m, t;

      m:= `if`(n=1, 0, a(n-1));

      l:= NULL;

      for t while m>0 do l:= l, irem(m, 3, 'm') od;

      l:= array([l, 0]);

      for i while l[i]=2 do od;

      if l[i]=0 then l[i]:= 1

                else l[i]:= 2;

                     if i>1 then l[i-1]:= 1 fi

      fi;

      add(l[i] *3^(i-1), i=1..t)

    end:

seq(a(n), n=1..100);  # Alois P. Heinz, Apr 02 2011

MATHEMATICA

okQ[n_]:=DigitCount[n, 3, 0]==0&&DigitCount[n, 3, 1]<2; Select[Range[20000], okQ]  (* Harvey P. Dale, Apr 16 2011 *)

CROSSREFS

Cf. A062756, A077267.

Sequence in context: A275410 A139481 A340326 * A238364 A342730 A227445

Adjacent sequences:  A188338 A188339 A188340 * A188342 A188343 A188344

KEYWORD

nonn,base

AUTHOR

Vladimir Shevelev, Apr 02 2011

STATUS

approved

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Last modified June 22 04:06 EDT 2021. Contains 345367 sequences. (Running on oeis4.)