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.

A167024 Triangle read by rows: T(n, m) = binomial(n, m)* Sum_{k=0..m} binomial(n, k) for 0 <= m <= n.

Original entry on oeis.org

1, 1, 2, 1, 6, 4, 1, 12, 21, 8, 1, 20, 66, 60, 16, 1, 30, 160, 260, 155, 32, 1, 42, 330, 840, 855, 378, 64, 1, 56, 609, 2240, 3465, 2520, 889, 128, 1, 72, 1036, 5208, 11410, 12264, 6916, 2040, 256, 1, 90, 1656, 10920, 32256, 48132, 39144, 18072, 4599, 512
Offset: 0

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Author

Roger L. Bagula, Oct 27 2009

Keywords

Comments

Row sums are A032443(n).

Examples

			1,
1, 2,
1, 6, 4,
1, 12, 21, 8,
1, 20, 66, 60, 16,
1, 30, 160, 260, 155, 32,
1, 42, 330, 840, 855, 378, 64,
1, 56, 609, 2240, 3465, 2520, 889, 128,
1, 72, 1036, 5208, 11410, 12264, 6916, 2040, 256,
1, 90, 1656, 10920, 32256, 48132, 39144, 18072, 4599, 512,
1, 110, 2520, 21120, 81060, 160776, 178080, 116160, 45585, 10230, 1024
		

Crossrefs

Programs

  • GAP
    t:=Flat(List([0..10],n->List([0..n],m->Binomial(n,m)*Sum([0..m],k->Binomial(n,k)))));; Print(t); # Muniru A Asiru, Dec 28 2018
  • Maple
    T:=(n, m)-> binomial(n, m)*add(binomial(n, k), k=0..m): seq(seq(T(n, m), m=0..n), n=0..9); # Muniru A Asiru, Dec 28 2018
  • Mathematica
    T[m_, n_] = If[m == 0 && n == 0, 1, Sum[Binomial[m, n]*Binomial[m, k], {k, 0, n}]]
    Flatten[Table[Table[T[m, n], {n, 0, m}], {m, 0, 10}]]
    T[n_,k_] := Binomial[n, k] (2^n - Binomial[n, k + 1] Hypergeometric2F1[1, 1 -n + k, k + 2, -1]); Table[T[n,k], {n,0,8}, {k,0,n}] // Flatten (* Peter Luschny, Dec 28 2018 *)

Formula

T(n, m) = binomial(n,m)*A008949(n,m). [Nov 03 2009]
G.f.: (1/x)*d(arctanh(N(x,y)))/dy, where N(x,y) is g.f. of Narayana numbers (A001263). - Vladimir Kruchinin, Apr 11 2018
T(n, k) = binomial(n, k)*(2^n - binomial(n, 1+k)*hypergeom([1, 1+k-n], [k+2], -1)). - Peter Luschny, Dec 28 2018

Extensions

Introduced OEIS notational standards in the definition - The Assoc. Editors of the OEIS, Nov 05 2009