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.

A329959 Binomial transform of a signed variant of triangle A050166.

Original entry on oeis.org

1, 0, 2, 0, 0, 5, 0, 0, 1, 14, 0, 0, 1, 8, 42, 0, 0, 1, 10, 45, 132, 0, 0, 1, 12, 69, 220, 429, 0, 0, 1, 14, 98, 406, 1001, 1430, 0, 0, 1, 16, 132, 672, 2184, 4368, 4862, 0, 0, 1, 18, 171, 1032, 4152, 11088, 18564, 16796, 0, 0, 1, 20, 215, 1500, 7185, 23904, 54060, 77520, 58786
Offset: 0

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Author

Gary W. Adamson, Nov 25 2019

Keywords

Comments

Row sums = A007317(n+1).
Right border = A000108(n+1).

Examples

			The signed variant of A050166 is A050166(n,k) * (-1)^(n+k):
   1;
  -1,   2;
   1,  -4,   5;
  -1,   6, -14,  14;
   1,  -8,  27, -48,  42;
  ...
Let the above triangle = S, and Pascal's triangle = P as an infinite lower triangular matrix. Then T = P * S gives:
  1;
  0,   2;
  0,   0,   5;
  0,   0,   1,  14;
  0,   0,   1,   8,  42;
  0,   0,   1,  10,  45, 132;
  ...
		

Crossrefs

Programs

  • GAP
    B:=Binomial;; Flat(List([0..10], n-> List([0..n], k-> Sum([k..n], j-> (-1)^(k+j)*B(n,j)*(B(2*j,k) - B(2*j,k-2)) )))); # G. C. Greubel, Jan 06 2020
  • Magma
    T:= func< n,k | &+[(-1)^(k+j)*Binomial(n,j)*(Binomial(2*j,k) - Binomial(2*j,k-2)): j in [k..n]] >;
    [T(n,k): k in [0..n], n in [0..10]]; // G. C. Greubel, Jan 06 2020
    
  • Maple
    S:= (n, k)-> (binomial(2*n, k)-binomial(2*n, k-2))*(-1)^(n+k):
    T:= (n, k)-> add(binomial(n, j)*S(j, k), j=k..n):
    seq(seq(T(n, k), k=0..n), n=0..10);  # Alois P. Heinz, Nov 27 2019
  • Mathematica
    Table[Sum[(-1)^(k+j)*Binomial[n, j]*(Binomial[2*j, k] - Binomial[2*j, k-2]), {j, k, n}], {n,0,10}, {k,0,n}]//Flatten (* G. C. Greubel, Jan 06 2020 *)
  • PARI
    T(n,k) = sum(j=k, n, (-1)^(k+j)*binomial(n,j)*(binomial(2*j,k) - binomial(2*j,k-2)) ); \\ G. C. Greubel, Jan 06 2020
    
  • Sage
    [[sum((-1)^(k+j)*binomial(n,j)*(binomial(2*j,k) - binomial(2*j,k-2)) for j in (k..n)) for k in (0..n)] for n in (0..10)] # G. C. Greubel, Jan 06 2020
    

Formula

T(n,k) = Sum_{j=k..n} C(n,j) * (-1)^(j+k) * A050166(j,k). - Alois P. Heinz, Nov 27 2019

Extensions

New offset and more terms from Alois P. Heinz, Nov 25 2019