cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A142243 Triangle T(n,k) = binomial(2*n,k) *binomial(2*n-2*k,n-k), read by rows; 0<=k<=n.

Original entry on oeis.org

1, 2, 2, 6, 8, 6, 20, 36, 30, 20, 70, 160, 168, 112, 70, 252, 700, 900, 720, 420, 252, 924, 3024, 4620, 4400, 2970, 1584, 924, 3432, 12936, 22932, 25480, 20020, 12012, 6006, 3432, 12870, 54912, 110880, 141120, 127400, 87360, 48048, 22880, 12870, 48620
Offset: 0

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Author

Roger L. Bagula and Gary W. Adamson, Sep 17 2008

Keywords

Comments

Row sums are s(n) = 1, 4, 20, 106, 580, 3244,,...

Examples

			1;
2, 2;
6, 8, 6;
20, 36, 30, 20;
70, 160, 168, 112, 70;
252, 700, 900, 720, 420, 252;
924, 3024, 4620, 4400, 2970, 1584, 924;
3432, 12936, 22932, 25480, 20020, 12012, 6006, 3432;
12870, 54912, 110880, 141120, 127400, 87360, 48048, 22880, 12870;
48620, 231660, 525096, 753984, 771120, 599760, 371280, 190944, 87516, 48620';
184756, 972400, 2445300, 3912480, 4476780, 3907008, 2713200, 1550400, 755820, 335920, 184756;
		

Crossrefs

Cf. A062344.

Programs

  • Mathematica
    t[n_, m_] = (Binomial[2*n, m]*Binomial[2*(n - m), (n - m)]); Table[Table[t[n, m], {m, 0, n}], {n, 0, 10}]; Flatten[%]

Formula

Conjecture for row sums: 2*(n+1)*(2*n+1)*s(n) +(-81*n^2+19*n-8)*s(n-1) +10*(51*n^2-77*n+30)*s(n-2) -500*(n-1)*(2*n-3)*s(n-3)=0. - R. J. Mathar, Sep 13 2013