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A341910
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Lexicographically earliest sequence of distinct nonnegative integers such that for any n >= 0, the number of runs in the binary expansion of n equals the number of ones in the binary expansion of a(n).
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2
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0, 1, 3, 2, 5, 7, 6, 4, 9, 11, 15, 13, 10, 14, 12, 8, 17, 19, 23, 21, 27, 31, 29, 22, 18, 25, 30, 26, 20, 28, 24, 16, 33, 35, 39, 37, 43, 47, 45, 38, 46, 55, 63, 59, 51, 61, 53, 41, 34, 42, 54, 44, 57, 62, 58, 49, 36, 50, 60, 52, 40, 56, 48, 32, 65, 67, 71, 69
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OFFSET
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0,3
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COMMENTS
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This sequence is a permutation of the nonnegative integers with inverse A341911.
Apparently, A037481 corresponds to the fixed points of this sequence.
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LINKS
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FORMULA
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a(n) < 2^k for any n < 2^k.
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EXAMPLE
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The first terms, in decimal and in binary, are:
n a(n) bin(n) bin(a(n))
-- ---- ------- ---------
0 0 0 0
1 1 1 1
2 3 10 11
3 2 11 10
4 5 100 101
5 7 101 111
6 6 110 110
7 4 111 100
8 9 1000 1001
9 11 1001 1011
10 15 1010 1111
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MATHEMATICA
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Block[{a = {0}, k}, Do[k = 1; While[Nand[FreeQ[a, k], DigitCount[k, 2, 1] == #], k++] &@ Length[Split@ IntegerDigits[i, 2]]; AppendTo[a, k], {i, 67}]; a] (* Michael De Vlieger, Feb 24 2021 *)
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PROG
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(PARI) See Links section.
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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