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.

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A109906 A triangle based on A000045 and Pascal's triangle: T(n,m) = Fibonacci(n-m+1) * Fibonacci(m+1) * binomial(n,m).

Original entry on oeis.org

1, 1, 1, 2, 2, 2, 3, 6, 6, 3, 5, 12, 24, 12, 5, 8, 25, 60, 60, 25, 8, 13, 48, 150, 180, 150, 48, 13, 21, 91, 336, 525, 525, 336, 91, 21, 34, 168, 728, 1344, 1750, 1344, 728, 168, 34, 55, 306, 1512, 3276, 5040, 5040, 3276, 1512, 306, 55, 89, 550, 3060, 7560, 13650, 16128, 13650, 7560, 3060, 550, 89
Offset: 0

Views

Author

Roger L. Bagula and Gary W. Adamson, Aug 24 2008

Keywords

Comments

Row sums give A081057.

Examples

			Triangle T(n,k) begins:
   1;
   1,   1;
   2,   2,    2;
   3,   6,    6,    3;
   5,  12,   24,   12,     5;
   8,  25,   60,   60,    25,     8;
  13,  48,  150,  180,   150,    48,    13;
  21,  91,  336,  525,   525,   336,    91,   21;
  34, 168,  728, 1344,  1750,  1344,   728,  168,   34;
  55, 306, 1512, 3276,  5040,  5040,  3276, 1512,  306,  55;
  89, 550, 3060, 7560, 13650, 16128, 13650, 7560, 3060, 550, 89;
  ...
		

Crossrefs

Some other Fibonacci-Pascal triangles: A027926, A036355, A037027, A074829, A105809, A111006, A114197, A162741, A228074.

Programs

  • Haskell
    a109906 n k = a109906_tabl !! n !! k
    a109906_row n = a109906_tabl !! n
    a109906_tabl = zipWith (zipWith (*)) a058071_tabl a007318_tabl
    -- Reinhard Zumkeller, Aug 15 2013
  • Maple
    f:= n-> combinat[fibonacci](n+1):
    T:= (n, k)-> binomial(n, k)*f(k)*f(n-k):
    seq(seq(T(n, k), k=0..n), n=0..10);  # Alois P. Heinz, Apr 26 2023
  • Mathematica
    Clear[t, n, m] t[n_, m_] := Fibonacci[(n - m + 1)]*Fibonacci[(m + 1)]*Binomial[n, m]; Table[Table[t[n, m], {m, 0, n}], {n, 0, 10}]; Flatten[%]

Formula

T(n,m) = Fibonacci(n-m+1)*Fibonacci(m+1)*binomial(n,m).
T(n,k) = A058071(n,k) * A007318(n,k). - Reinhard Zumkeller, Aug 15 2013

Extensions

Offset changed by Reinhard Zumkeller, Aug 15 2013

A114198 a(n) = Sum_{k=0..n} binomial(n,k)^2*F(k+1).

Original entry on oeis.org

1, 2, 7, 31, 142, 659, 3113, 14918, 72199, 351983, 1726022, 8504509, 42070429, 208812722, 1039387519, 5186451311, 25935769702, 129942777227, 652133298421, 3277734587302, 16496741964221, 83129076840317, 419362231888882
Offset: 0

Views

Author

Paul Barry, Nov 16 2005

Keywords

Crossrefs

Programs

  • Maple
    a:= proc(n) option remember; `if`(n<4, [1, 2, 7, 31][n+1],
         ((3*(n-1))*(2*n-5)*(13*n^2-26*n+10) *a(n-1)
          -(7*n^2-14*n+6)*(13*n^2-52*n+49) *a(n-2)
          +(n-2)*(182*n^3-819*n^2+1050*n-351) *a(n-3)
          -(n-2)*(n-3)*(13*n^2-26*n+10) *a(n-4))/
          (n*(n-1)*(13*n^2-52*n+49)))
        end:
    seq(a(n), n=0..25);  # Alois P. Heinz, Sep 28 2016
  • Mathematica
    FullSimplify@Table[(GoldenRatio^(n - 1) LegendreP[n, Sqrt[5] - 2] - (1 - GoldenRatio)^(n - 1) LegendreP[n, -Sqrt[5] - 2])/Sqrt[5], {n, 0, 20}] (* Vladimir Reshetnikov, Sep 28 2016 *)

Formula

a(n) = Sum_{k=0..n} C(n, k)^2 * F(k+1); a(n) = A114197(2n, n).
a(n) = (phi^(n-1) * P_n(sqrt(5)-2) - (1-phi)^(n-1) * P_n(-sqrt(5)-2))/sqrt(5), where phi = (1+sqrt(5))/2, P_n(x) is the Legendre polynomial.
a(n) ~ sqrt((6 + 2*sqrt(5) + sqrt(2*(29 + 13*sqrt(5))))/10)/2 * ((3 + sqrt(5))/2 + sqrt(2*(1+sqrt(5))))^n / sqrt(Pi*n). - Vaclav Kotesovec, May 06 2017
a(n) ~ sqrt(2*phi^2 + phi^(7/2)) * (2*phi^(1/2) + phi^2)^n / (2*sqrt(5*Pi*n)), where phi = A001622 = (1+sqrt(5))/2 is the golden ratio. - Vaclav Kotesovec, Sep 22 2017
D-finite with recurrence +n*(n-1)*a(n) -5*n*(n-1)*a(n-1) +2*(-n^2+17*n-27)*a(n-2) +(11*n^2-135*n+270)*a(n-3) +2*(-17*n^2+121*n-215)*a(n-4) +(n-4)*(43*n-191)*a(n-5) -3*(n-4)*(n-5)*a(n-6)=0. - R. J. Mathar, May 11 2022

A114199 Row sums of a Pascal-Fibonacci triangle.

Original entry on oeis.org

1, 2, 4, 8, 17, 38, 87, 200, 458, 1044, 2373, 5388, 12233, 27782, 63112, 143392, 325805, 740266, 1681935, 3821412, 8682310, 19726316, 44818473, 101828344, 231355953, 525645354, 1194276812, 2713420728, 6164945513, 14006877390
Offset: 0

Views

Author

Paul Barry, Nov 16 2005

Keywords

Comments

Binomial transform of double Fibonacci sequence A103609(n+2). Row sums of A114197.

Crossrefs

Programs

  • Magma
    [n le 4 select 2^(n-1) else 4*Self(n-1) -5*Self(n-2) +2*Self(n-3) +Self(n-4): n in [1..30]]; // G. C. Greubel, Oct 23 2024
    
  • Mathematica
    LinearRecurrence[{4,-5,2,1},{1,2,4,8},30] (* Harvey P. Dale, Dec 07 2015 *)
  • SageMath
    @CachedFunction # a = A114199
    def a(n): return 2^n if n<4 else 4*a(n-1) -5*a(n-2) +2*a(n-3) +a(n-4)
    [a(n) for n in range(71)] # G. C. Greubel, Oct 23 2024

Formula

G.f.: (1-x)^2/(1-4*x+5*x^2-2*x^3-x^4).
a(n) = Sum_{k=0..n} Sum_{j=0..n-k} C(n-k, j)*C(k, j)*Fibonacci(j).
a(n) = Sum_{k=0..n} C(n, k)*Fibonacci(floor((k+2)/2)).
Previous Showing 11-13 of 13 results.