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 A036990 Numbers n such that, in the binary expansion of n, reading from right to left, the number of 1's never exceeds the number of 0's. 10
 0, 2, 4, 8, 10, 12, 16, 18, 20, 24, 32, 34, 36, 40, 42, 44, 48, 50, 52, 56, 64, 66, 68, 72, 74, 76, 80, 82, 84, 88, 96, 98, 100, 104, 112, 128, 130, 132, 136, 138, 140, 144, 146, 148, 152, 160, 162, 164, 168, 170, 172, 176, 178, 180, 184, 192, 194, 196, 200, 202, 204 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS A036989(a(n)) = 1. - Reinhard Zumkeller, Jul 31 2013 LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 H. Niederreiter and M. Vielhaber, Tree complexity and a doubly exponential gap between structured and random sequences, J. Complexity, 12 (1996), 187-198. FORMULA a(n) = 2*A095775(n). - Robert G. Wilson v MATHEMATICA fQ[n_] := Block[{od = ev = k = 0, id = Reverse@IntegerDigits[n, 2], lmt = Floor@Log[2, n] + 1}, While[k < lmt && od < ev + 1, If[OddQ@id[[k + 1]], od++, ev++ ]; k++ ]; If[k == lmt && od < ev + 1, True, False]]; Select[ Range[0, 204, 2], fQ@# &] (* Robert G. Wilson v, Jan 11 2007 *) (* b = A036989 *) b[0] = 1; b[n_?EvenQ] := b[n] = Max[b[n/2]-1, 1]; b[n_] := b[n] = b[(n-1)/2]+1; Select[Range[0, 300, 2], b[#] == 1 &] (* Jean-François Alcover, Nov 05 2013, after Reinhard Zumkeller *) PROG (Haskell) a036990 n = a036990_list !! (n-1) a036990_list = filter ((== 1) . a036989) [0..] -- Reinhard Zumkeller, Jul 31 2013 CROSSREFS Cf. A036988, A036991, A036992, A061854, A125086. Each term is 2^n * some term of A014486 (n >= 0). Cf. A030308. Sequence in context: A047464 A189786 A195066 * A097498 A224694 A140900 Adjacent sequences:  A036987 A036988 A036989 * A036991 A036992 A036993 KEYWORD nonn,easy,base AUTHOR EXTENSIONS More terms from Erich Friedman. STATUS approved

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Last modified October 17 19:36 EDT 2018. Contains 316293 sequences. (Running on oeis4.)