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.

A094436 Triangular array T(n,k) = Fibonacci(k+1)*binomial(n,k) for k = 0..n; n >= 0.

Original entry on oeis.org

1, 1, 1, 1, 2, 2, 1, 3, 6, 3, 1, 4, 12, 12, 5, 1, 5, 20, 30, 25, 8, 1, 6, 30, 60, 75, 48, 13, 1, 7, 42, 105, 175, 168, 91, 21, 1, 8, 56, 168, 350, 448, 364, 168, 34, 1, 9, 72, 252, 630, 1008, 1092, 756, 306, 55, 1, 10, 90, 360, 1050, 2016, 2730, 2520, 1530, 550, 89
Offset: 0

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Author

Clark Kimberling, May 03 2004

Keywords

Comments

Let F(n) denote the n-th Fibonacci number (A000045). Then n-th row sum of T is F(2n+1) and n-th alternating row sum is F(n-1).
A094436 is jointly generated with A094437 as a triangular array of coefficients of polynomials u(n,x): initially, u(1,x)=v(1,x)=1; for n>1, u(n,x) = u(n-1,x) + x*v(n-1,x) and v(n,x) = x*u(n-1,x) + (x+1)*v(n-1,x). See the Mathematica section. - Clark Kimberling, Feb 26 2012
Subtriangle of the triangle given by (1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, ...) DELTA (0, 1, 1, -1, 0, 0, 0, 0, 0, 0, 0, ...) where DELTA is the operator defined in A084938. - Philippe Deléham, Mar 26 2012
This sequence gives the coefficients of the Jensen polynomials (increasing powers of x) for the sequence {A000045(k)}{k >= 0} of degree n with shift 1. Here the definition of Jensen polynomials of degree n and shift m of an arbitrary real sequence {s(k)}{k >= 0} is used: J(s,m;n,x) := Sum_{j=0..n} binomial(n,j)*s(j + m)*x^j, This definition is used by Griffin et al. with a different notation. - Wolfdieter Lang, Jun 25 2019

Examples

			First four rows:
  1
  1 1
  1 2 2
  1 3 6 3
Sum = 1+3+6+3=13=F(7); alt.Sum = 1-3+6-3=1=F(2).
T(3,2)=F(3)C(3,2)=2*3=6.
From _Philippe Deléham_, Mar 26 2012: (Start)
(1, 0, 0, 1, 0, 0, 0, ...) DELTA (0, 1, 1, -1, 0, 0, 0, ...) begins :
  1
  1, 0
  1, 1, 0
  1, 2, 2, 0
  1, 3, 6, 3, 0
  1, 4, 12, 12, 5, 0
  1, 5, 20, 30, 25, 8, 0
  1, 6, 30, 60, 75, 48, 13, 0 . (End)
		

Crossrefs

Programs

  • GAP
    Flat(List([0..12], n-> List([0..n], k-> Fibonacci(k+1)* Binomial(n,k) ))); # G. C. Greubel, Jul 11 2019
  • Magma
    [Fibonacci(k+1)*Binomial(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Jul 11 2019
    
  • Maple
    with(combinat); seq(seq(fibonacci(k+1)*binomial(n,k), k=0..n), n=0..12); # G. C. Greubel, Oct 30 2019
  • Mathematica
    (* First program *)
    u[1, x_] := 1; v[1, x_] := 1; z = 13;
    u[n_, x_] := u[n - 1, x] + x*v[n - 1, x];
    v[n_, x_] := x*u[n - 1, x] + (x + 1)*v[n - 1, x];
    Table[Expand[u[n, x]], {n, 1, z/2}]
    Table[Expand[v[n, x]], {n, 1, z/2}]
    cu = Table[CoefficientList[u[n, x], x], {n, 1, z}];
    TableForm[cu]
    Flatten[%]  (* A094436 *)
    Table[Expand[v[n, x]], {n, 1, z}]
    cv = Table[CoefficientList[v[n, x], x], {n, 1, z}];
    TableForm[cv]
    Flatten[%]  (* A094437 *)
    (* Second program *)
    Table[Fibonacci[k+1]*Binomial[n, k], {n,0,12}, {k,0,n}]//Flatten (* G. C. Greubel, Jul 11 2019 *)
  • PARI
    T(n,k) = fibonacci(k+1)*binomial(n,k); \\ G. C. Greubel, Jul 11 2019
    
  • Sage
    [[fibonacci(k+1)*binomial(n,k) for k in (0..n)] for n in (0..12)] # G. C. Greubel, Jul 11 2019
    

Formula

T(n,k) = 2*T(n-1,k) + T(n-1,k-1) - T(n-2,k) - T(n-2,k-1) + T(n-2,k-2), T(0,0) = T(1,0) = T(1,1) = 1 and T(n,k) = 0 if k<0 or if k>n. - Philippe Deléham, Mar 26 2012
G.f. (-1+x)/(-1+2*x+x*y-x^2*y+x^2*y^2-x^2). - R. J. Mathar, Aug 11 2015
From G. C. Greubel, Oct 30 2019: (Start)
T(n, k) = binomial(n, k)*Fibonacci(k+1).
Sum_{k=0..n} T(n,k) = Fibonacci(2*n+1).
Sum_{k=0..n} (-1)^k*T(n,k) = Fibonacci(n-1). (End)

Extensions

Offset set to 0 by Alois P. Heinz, Aug 11 2015