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 A321464 Reverse nonzero digits in ternary expansion of n and convert back to decimal. 7
 0, 1, 2, 3, 4, 7, 6, 5, 8, 9, 10, 19, 12, 13, 22, 21, 16, 25, 18, 11, 20, 15, 14, 23, 24, 17, 26, 27, 28, 55, 30, 31, 58, 57, 34, 61, 36, 37, 64, 39, 40, 67, 66, 49, 76, 63, 46, 73, 48, 43, 70, 75, 52, 79, 54, 29, 56, 33, 32, 59, 60, 35, 62, 45, 38, 65, 42, 41 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS This sequence is a self-inverse permutation of nonnegative integers with fixed points A321473. See A321474 for the decimal variant. The binary variant simply corresponds to the identity (A001477). LINKS Rémy Sigrist, Table of n, a(n) for n = 0..19683 FORMULA a(3 * n) = 3 * a(n). EXAMPLE The first values at prime indices, alongside the corresponding ternary expansions, are:   n   a(n)  ter(n)  ter(a(n))   --  ----  ------  ---------    2     2       2          2    3     3      10         10    5     7      12         21    7     5      21         12   11    19     102        201   13    13     111        111   17    25     122        221   19    11     201        102   23    23     212        212   29    55    1002       2001   31    31    1011       1011   37    37    1101       1101   41    67    1112       2111   43    49    1121       1211 MATHEMATICA a[n_] := Block[{x = IntegerDigits[n, 3], t}, t = Flatten@ Position[x, 1 | 2]; x[[Reverse@ t]] = x[[t]]; FromDigits[x, 3]]; Array[a, 68, 0] (* Giovanni Resta, Sep 17 2019 *) PROG (PARI) a(n, base=3) = my (d=digits(n, base), t=Vecrev(select(sign, d)), i=0); for (j=1, #d, if (d[j], d[j] = t[i++])); fromdigits(d, base) CROSSREFS Cf. A001477, A004488, A030102, A321473, A321474. Sequence in context: A266643 A321525 A321524 * A263273 A337305 A264966 Adjacent sequences:  A321461 A321462 A321463 * A321465 A321466 A321467 KEYWORD nonn,base,look AUTHOR Rémy Sigrist, Nov 10 2018 STATUS approved

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Last modified June 21 12:19 EDT 2021. Contains 345364 sequences. (Running on oeis4.)