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.

A097207 Triangle read by rows: T(n,k) = binomial(n,k) + 2*binomial(n,k-1).

Original entry on oeis.org

1, 1, 3, 1, 4, 5, 1, 5, 9, 7, 1, 6, 14, 16, 9, 1, 7, 20, 30, 25, 11, 1, 8, 27, 50, 55, 36, 13, 1, 9, 35, 77, 105, 91, 49, 15, 1, 10, 44, 112, 182, 196, 140, 64, 17, 1, 11, 54, 156, 294, 378, 336, 204, 81, 19, 1, 12, 65, 210, 450, 672, 714, 540, 285, 100, 21, 1, 13, 77, 275, 660
Offset: 0

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Author

N. J. A. Sloane, Sep 21 2004

Keywords

Examples

			Triangle begins:
1
1 3
1 4 5
1 5 9 7
1 6 14 16 9
		

Crossrefs

Cf. A029637, A110813 (row-reversed).

Programs

  • Haskell
    a097207 n k = a097207_tabl !! n !! k
    a097207_row n = a097207_tabl !! n
    a097207_tabl = map init $ tail a029635_tabl
    -- Reinhard Zumkeller, Mar 12 2012
  • Mathematica
    T[n_, k_] := Binomial[n, k] + 2Binomial[n, k - 1]; Flatten[ Table[ T[n, k], {n, 0, 10}, {k, 0, n}]] (* Robert G. Wilson v, Sep 21 2004 *)

Formula

T(n,k) = A029635(n+1,k), 0 <= k <= n. - Reinhard Zumkeller, Mar 12 2012

Extensions

More terms from Robert G. Wilson v, Sep 21 2004