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A190868
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Let C(n) be the expected length of the longest carry chain when two n-bit binary numbers are added; sequence gives a(n) = 2^(2n-1)*C(n).
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1
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0, 14, 106, 598, 3002, 14142, 64106, 283166, 1228346, 5257966, 22281738, 93689246, 391512666, 1627925006, 6741353258, 27821715326, 114493140090, 470023545198, 1925545015370, 7874137194718, 32148981709466, 131077794504654, 533774656417642, 2171261671337534, 8823512782678714, 35825200435380270
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OFFSET
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2,2
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COMMENTS
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The addition is carried out by a parallel adder as described by J. von Neumann.
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LINKS
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Table of n, a(n) for n=2..27.
Volker Claus, Die mittlere Additionsdauer eines Paralleladdierwerks, Acta Informat. 2 (1973), 283-291.
D. E. Knuth, The average time for carry propagation, Nederl. Akad. Wetensch. Indag. Math., 81 (2) (1978), 238-242.
Nicholas Pippenger, Analysis of carry propagation in addition: an elementary approach, J. Algorithms 42 (2002), 317-333.
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FORMULA
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C(n) = E(n)-1, where E(n) is defined in A190866.
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EXAMPLE
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C(n) for n >= 2: 0, 7/16, 53/64, 299/256, 1501/1024, 7071/4096, 32053/16384, 141583/65536, ...
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MAPLE
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See A190866.
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CROSSREFS
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Cf. A190866.
Sequence in context: A285752 A076128 A206761 * A125351 A126509 A200056
Adjacent sequences: A190865 A190866 A190867 * A190869 A190870 A190871
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KEYWORD
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nonn,frac
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AUTHOR
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R. J. Mathar and N. J. A. Sloane, May 22 2011
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STATUS
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approved
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