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Search: id:A144079
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| A144079 |
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a(n) = the number of digits in the binary representation of n that each equal the respective digit in the binary reversal of n. (ie a(n) = number of 0's in n XOR A030101(n).) |
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+0
2
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| 1, 0, 2, 1, 3, 1, 3, 2, 4, 0, 2, 0, 2, 2, 4, 3, 5, 1, 3, 3, 5, 1, 3, 1, 3, 3, 5, 1, 3, 3, 5, 4, 6, 2, 4, 2, 4, 0, 2, 2, 4, 0, 2, 4, 6, 2, 4, 2, 4, 4, 6, 0, 2, 2, 4, 0, 2, 2, 4, 2, 4, 4, 6, 5, 7, 3, 5, 3, 5, 1, 3, 5, 7, 3, 5, 3, 5, 1, 3, 3, 5, 1, 3, 5, 7, 3, 5, 3, 5, 1, 3, 5, 7, 3, 5, 3, 5, 5, 7, 1, 3, 3, 5, 3, 5
(list; graph; listen)
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OFFSET
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1,3
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COMMENT
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A144078(n) + A144079(n) = A070939(n), the number of binary digits in n.
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LINKS
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Leroy Quet, Home Page (listed in lieu of email address)
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EXAMPLE
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20 in binary is 10100. Compare this with its digit reversal, 00101. XOR each pair of respective digits: 1 XOR 0 = 1, 0 XOR 0 = 0, 1 XOR 1 = 0, 0 XOR 0 = 0, 0 XOR 1 = 1. There are three bit pairs that contain the same values, so a(20) = 3.
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MAPLE
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A144079 := proc(n) local a, dgs, i; a := 0 ; dgs := convert(n, base, 2) ; for i from 1 to nops(dgs) do if op(i, dgs)+op(-i, dgs) <> 1 then a := a+1 ; fi; od; RETURN(a) ; end: for n from 1 to 240 do printf("%d, ", A144079(n)) ; od: [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 14 2008]
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CROSSREFS
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A030101, A144078
Sequence in context: A109698 A029231 A025808 this_sequence A071575 A038569 A020650
Adjacent sequences: A144076 A144077 A144078 this_sequence A144080 A144081 A144082
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KEYWORD
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base,nonn
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AUTHOR
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Leroy Quet Sep 09 2008
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EXTENSIONS
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More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 14 2008
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