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A144078
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a(n) = the number of digits in the binary representation of n that each differ from the respective digit in the binary reversal of n. (ie a(n) = number of 1's in n XOR A030101(n).)
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2
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0, 2, 0, 2, 0, 2, 0, 2, 0, 4, 2, 4, 2, 2, 0, 2, 0, 4, 2, 2, 0, 4, 2, 4, 2, 2, 0, 4, 2, 2, 0, 2, 0, 4, 2, 4, 2, 6, 4, 4, 2, 6, 4, 2, 0, 4, 2, 4, 2, 2, 0, 6, 4, 4, 2, 6, 4, 4, 2, 4, 2, 2, 0, 2, 0, 4, 2, 4, 2, 6, 4, 2, 0, 4, 2, 4, 2, 6, 4, 4, 2, 6, 4, 2, 0, 4, 2, 4, 2, 6, 4, 2, 0, 4, 2, 4, 2, 2, 0, 6, 4, 4, 2, 4, 2
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| A144078(n) + A144079(n) = A070939(n), the number of binary digits in n.
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EXAMPLE
| 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 two bit pairs that differ, so a(20) = 2.
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MAPLE
| A144078 := 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, ", A144078(n)) ; od: [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 14 2008]
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CROSSREFS
| A030101, A144079
Sequence in context: A181587 A096158 A053471 * A008614 A036663 A096577
Adjacent sequences: A144075 A144076 A144077 * A144079 A144080 A144081
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KEYWORD
| base,nonn
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AUTHOR
| Leroy Quet, Sep 09 2008
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EXTENSIONS
| More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 14 2008
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