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Search: id:A013701
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| A013701 |
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Degree of variety K_{2,n}^4. |
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+0
5
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| 1, 512, 75025, 7174454, 562110290, 39541748736, 2610763825782, 165745451110910, 10262482704258873, 625250747214775916, 37701606156514031251, 2258713106034310399852, 134810129909509070121060
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OFFSET
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1,2
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COMMENT
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Number of Catalan paths (nonnegative, starting and ending at 0, step +/-1) of 6n+8 steps with all values less than or equal to n+1 (see A080934).
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LINKS
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M. S. Ravi et al., Dynamic pole assignment and Schubert calculus, SIAM J. Control Optimization, 34 (1996), 813-832, esp. p. 825.
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PROGRAM
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(PARI) K(n, q=4)=(2*n+n*q+2*q)!*sum(j=0, q, ((q-2*j)*(n+2)+1)/(n+j*(n+2))!/(n+1+(q-j)*(n+2))!)
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CROSSREFS
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Cf. A013698 (q=1), A013699 (q=2), A013700 (q=3), A013702 (q=5).
Sequence in context: A096962 A035753 A107549 this_sequence A016749 A144323 A016797
Adjacent sequences: A013698 A013699 A013700 this_sequence A013702 A013703 A013704
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KEYWORD
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nonn,easy
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AUTHOR
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Joachim.Rosenthal(AT)nd.edu (Joachim Rosenthal)
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