

A273008


a(n)/(4^(n1)*(4^n  1)) is the variance of the length of a longest common subsequence between two random binary strings of the length n.


0



1, 23, 476, 9463, 179708, 3285359, 58821148, 1036541808, 18048642524, 311226939840, 5325007685376, 90541291530096, 1531388084625152
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OFFSET

1,2


COMMENTS

A027433(n)/4^n gives the expected value of the length of a longest common subsequence between two random binary strings of the length n, and a(n)/(4^(n1)*(4^n  1)) gives the variance (the squared standard deviation) of that length.


LINKS

Table of n, a(n) for n=1..13.
Vacláv Chvátal, David Sankoff, Longest Common Subsequences of Two Random Sequences, Journal of Applied Probability, Vol. 12, No. 2 (Jun., 1975), pp. 306315, DOI: 10.2307/3212444.
Wikipedia, ChvátalSankoff_constants.


CROSSREFS

Cf. A027433.
Sequence in context: A036906 A134733 A095256 * A015678 A293083 A014905
Adjacent sequences: A273005 A273006 A273007 * A273009 A273010 A273011


KEYWORD

nonn,hard,more


AUTHOR

Vladimir Reshetnikov, May 13 2016


STATUS

approved



