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Search: id:A087276
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| A087276 |
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Write n in binary: 1ab..yz, then a(n) = 1ab..yz + ... + 1yz + 1z + 1. |
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+0
2
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| 1, 3, 4, 7, 9, 9, 11, 15, 18, 19, 22, 19, 22, 23, 26, 31, 35, 37, 41, 39, 43, 45, 49, 39, 43, 45, 49, 47, 51, 53, 57, 63, 68, 71, 76, 75, 80, 83, 88, 79, 84, 87, 92, 91, 96, 99, 104, 79, 84, 87, 92, 91, 96, 99, 104, 95, 100, 103, 108, 107, 112, 115
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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a(n) = A087275(n) + n.
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FORMULA
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a(1) = 1, a(2n) = 2a(n) + 1, a(2n+1) = 2a(n) + [log2(n)] + 2.
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PROGRAM
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(PARI) a(n)=local(v, s, l):v=binary(n):l=length(v):s=0:for(k=2, l, s=s+2^(l-k)+sum(m=k+1, l, v[m]*2^(l-m))):s+n
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CROSSREFS
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Cf. A005187, A059893, A059894.
Sequence in context: A130420 A101715 A075773 this_sequence A138225 A114889 A010444
Adjacent sequences: A087273 A087274 A087275 this_sequence A087277 A087278 A087279
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KEYWORD
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nonn,easy
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AUTHOR
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Ralf Stephan (ralf(AT)ark.in-berlin.de), Aug 27 2003
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