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A168151
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Riordan array (1/u,(1-u)/2), u=sqrt(1-4x+4*x^3).
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1
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1, 2, 1, 6, 3, 1, 18, 9, 4, 1, 58, 29, 13, 5, 1, 192, 96, 44, 18, 6, 1, 650, 325, 151, 64, 24, 7, 1, 2232, 1116, 524, 228, 90, 31, 8, 1, 7746, 3873, 1833, 813, 333, 123, 39, 9, 1, 27096, 13548, 6452, 2904, 1222, 473, 164, 48, 10, 1
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OFFSET
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0,2
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COMMENTS
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T(n,0) = A157004(n).
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REFERENCES
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Baccherini, D.; Merlini, D.; Sprugnoli, R. Binary words excluding a pattern and proper Riordan arrays. Discrete Math. 307 (2007), no. 9-10, 1021--1037. MR2292531 (2008a:05003). See Example 5.6. - N. J. A. Sloane, Mar 25 2014
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LINKS
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Table of n, a(n) for n=0..54.
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FORMULA
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T(n,0)=2*T(n,1) for n>0, T(0,0)=1, T(n,k)=T(n-1,k-1)-T((n-3,k-1)+T(n,k+1).
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EXAMPLE
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Triangle begins :
1
2 1
6 3 1
18 9 4 1
58 29 13 5 1
192 96 44 18 6 1
650 325 151 64 24 7 1
...
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CROSSREFS
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Cf. A025262, A157004
Sequence in context: A046803 A280789 A121468 * A213221 A180281 A187888
Adjacent sequences: A168148 A168149 A168150 * A168152 A168153 A168154
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KEYWORD
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nonn,tabl
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AUTHOR
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Philippe Deléham, Nov 19 2009
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STATUS
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approved
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