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 A081607 Number of numbers <= n having at least one 0 in their ternary representation. 6
 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 5, 6, 7, 7, 7, 8, 8, 8, 9, 10, 11, 12, 12, 12, 13, 13, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 26, 26, 27, 27, 27, 28, 29, 30, 31, 31, 31, 32, 32, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 45, 45, 46, 46, 46, 47, 48, 49, 50 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 COMMENTS a(n) + A081608(n) = n+1. LINKS Robert Israel, Table of n, a(n) for n = 0..10000 MAPLE f:= n -> `if`(has(convert(n, base, 3), 0), 1, 0): ListTools:-PartialSums(map(f, [\$0..100])); # Robert Israel, Mar 18 2018 MATHEMATICA Accumulate[Boole[Table[DigitCount[n, 3, 0]>0, {n, 0, 80}]]] (* Harvey P. Dale, Jun 23 2017 *) PROG (PARI) first(n)=my(s, t); vector(n, k, t=Set(digits(k, 3)); s+=(t[1]==0)) \\ Charles R Greathouse IV, Sep 02 2015 CROSSREFS Cf. A007089, A077267, A081609, A081610. Sequence in context: A029061 A337206 A334576 * A029060 A184258 A219291 Adjacent sequences:  A081604 A081605 A081606 * A081608 A081609 A081610 KEYWORD nonn AUTHOR Reinhard Zumkeller, Mar 23 2003 STATUS approved

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Last modified April 11 06:11 EDT 2021. Contains 342886 sequences. (Running on oeis4.)