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A211676
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Number of n-bit numbers in A077436.
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1
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1, 1, 2, 3, 4, 5, 6, 9, 14, 24, 37, 63, 93, 162, 233, 376, 582, 921, 1497, 2435, 4007, 6696, 10998, 18310, 30340, 50792, 84897, 143079, 239266, 401652, 673887, 1131226, 1900203, 3197114, 5373366, 9039360, 15208992, 25592325, 43064747, 72494816, 122025100
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listen;
history;
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internal format)
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OFFSET
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0,3
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COMMENTS
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That is, the number of binary numbers b having n bits and B(b) = B(b^2), where the function B counts the number of ones in a binary number. For numbers written in base 10, the corresponding sequence is A147523.
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LINKS
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Table of n, a(n) for n=0..40.
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MATHEMATICA
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Join[{1}, Table[cnt = 0; Do[If[Total[IntegerDigits[i, 2]] == Total[IntegerDigits[i^2, 2]], cnt++], {i, 2^(n-1), 2^n-1}]; cnt, {n, 15}]]
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CROSSREFS
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Cf. A077436, A147523.
Sequence in context: A113444 A200444 A211697 * A076299 A136683 A200332
Adjacent sequences: A211673 A211674 A211675 * A211677 A211678 A211679
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KEYWORD
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nonn,hard,base
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AUTHOR
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T. D. Noe, Apr 27 2012
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EXTENSIONS
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a(28)-a(38) from Donovan Johnson, Apr 29 2012
a(39)-a(40) from Donovan Johnson, Aug 25 2012
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STATUS
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approved
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