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 A032863 Numbers whose base-8 representation Sum_{i=0..m} d(i)*8^i has d(m) > d(m-1) < d(m-2) > ... 3
 0, 1, 2, 3, 4, 5, 6, 7, 8, 16, 17, 24, 25, 26, 32, 33, 34, 35, 40, 41, 42, 43, 44, 48, 49, 50, 51, 52, 53, 56, 57, 58, 59, 60, 61, 62, 65, 66, 67, 68, 69, 70, 71, 129, 130, 131, 132, 133, 134, 135, 138, 139, 140, 141, 142, 143, 193, 194, 195 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Base-8 digits must be strictly alternating in size: every other digit must be strictly less than its neighbor(s). Also: numbers whose base-8 expansion, considered as a decimal number, is in A032865 = the base-10 variant of this sequence. - M. F. Hasler, Oct 05 2018 LINKS EXAMPLE From M. F. Hasler, Oct 05 2018: (Start) The base-8 representation of 7, 8, 16, 17, 24, 25, 26, 32, 33 is 7, 10, 20, 21, 30, 31, 32, 40, 41. Numbers 61, 62, 65, 66, ..., 70, 71, 129, 130, ... have the base-8 expansion 76, 77, 101, 102, ..., 106, 107, 201, 202, ... (End) MATHEMATICA sdQ[n_]:=Module[{s=Sign[Differences[IntegerDigits[n, 8]]]}, s==PadRight[{}, Length[s], {-1, 1}]]; Select[Range[0, 700], sdQ] (* Vincenzo Librandi, Oct 06 2018 *) PROG (PARI) is(n)=!for(i=2, #n=digits(n, 8), (n[i-1]-n[i])*(-1)^i>0||return) \\ M. F. Hasler, Oct 05 2018 CROSSREFS Cf. A032858, A032859, A032860, A032861, A032862, this sequence, A032864, A032865 for bases 3 to 10. Sequence in context: A319724 A097546 A004837 * A032887 A023790 A032943 Adjacent sequences:  A032860 A032861 A032862 * A032864 A032865 A032866 KEYWORD nonn,base AUTHOR EXTENSIONS a(1) = 0 added by Vincenzo Librandi, Oct 06 2018 STATUS approved

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Last modified May 16 19:46 EDT 2021. Contains 343951 sequences. (Running on oeis4.)