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.

Showing 1-5 of 5 results.

A202453 Fibonacci self-fusion matrix, by antidiagonals.

Original entry on oeis.org

1, 1, 1, 2, 2, 2, 3, 3, 3, 3, 5, 5, 6, 5, 5, 8, 8, 9, 9, 8, 8, 13, 13, 15, 15, 15, 13, 13, 21, 21, 24, 24, 24, 24, 21, 21, 34, 34, 39, 39, 40, 39, 39, 34, 34, 55, 55, 63, 63, 64, 64, 63, 63, 55, 55, 89, 89, 102, 102, 104, 104, 104, 102, 102, 89, 89, 144, 144, 165, 165
Offset: 1

Views

Author

Clark Kimberling, Dec 19 2011

Keywords

Comments

The Fibonacci self-fusion matrix, F, is the fusion P**Q, where P and Q are the lower and upper triangular Fibonacci matrices. See A193722 for the definition of fusion of triangular arrays.
Every term F(n,k) of F is a product of two Fibonacci numbers; indeed,
F(n,k)=F(n)*F(k+1) if k is even;
F(n,k)=F(n+1)*F(k) if k is odd.
antidiagonal sums: (1,2,6,12,...), A054454
diagonal (1,2,6,15,...), A001654
diagonal (1,3,9,24,...), A064831
diagonal (2,5,15,39,..), A059840
diagonal (3,8,24,63,..), A080097
diagonal (5,13,39,102,...), A080143
diagonal (8,21,63,165,...), A080144
principal submatrix sums, A202462
All the principal submatrices are invertible, and the terms in the inverses are in {-3,-2,-1,0,1,2,3}.

Examples

			Northwest corner:
1...1....2....3....5....8....13
1...2....3....5....8...13....21
2...3....6....9...15...24....39
3...5....9...15...24...39....63
5...8...15...24...40...64...104
		

Crossrefs

Cf. A000045, A202451, A202452, A202503 (Fibonacci fission array).

Programs

  • Mathematica
    n = 12;
    Q = NestList[Most[Prepend[#, 0]] &, #, Length[#] - 1] &[Table[Fibonacci[k], {k, 1, n}]];
    P = Transpose[Q]; F = P.Q;
    Flatten[Table[P[[i]][[k + 1 - i]], {k, 1, n}, {i, 1, k}]] (* A202452 as a sequence *)
    Flatten[Table[Q[[i]][[k + 1 - i]], {k, 1, n}, {i, 1, k}]] (* A202451 as a sequence *)
    Flatten[Table[F[[i]][[k + 1 - i]], {k, 1, n}, {i, 1, k}]] (* A202453 as a sequence *)
    TableForm[Q]  (* A202451, upper tri. Fibonacci array *)
    TableForm[P]  (* A202452, lower tri. Fibonacci array *)
    TableForm[F]  (* A202453, Fibonacci fusion array *)
    TableForm[FactorInteger[F]]

Formula

Matrix product P*Q, where P, Q are the lower and upper triangular Fibonacci matrices, A202451 and A202452.

A202503 Fibonacci self-fission matrix, by antidiagonals.

Original entry on oeis.org

1, 1, 2, 2, 3, 3, 3, 5, 5, 5, 5, 8, 9, 8, 8, 8, 13, 14, 15, 13, 13, 13, 21, 23, 24, 24, 21, 21, 21, 34, 37, 39, 39, 39, 34, 34, 34, 55, 60, 63, 64, 63, 63, 55, 55, 55, 89, 97, 102, 103, 104, 102, 102, 89, 89, 89, 144, 157, 165, 167, 168, 168, 165, 165, 144, 144, 144
Offset: 1

Views

Author

Clark Kimberling, Dec 20 2011

Keywords

Comments

The Fibonacci self-fission matrix, F, is the fission P^^Q, where P and Q are the matrices given at A202502 and A202451. See A193842 for the definition of fission.
antidiagonal sums: (1, 3, 8, 18, 38, ...), A064831
diagonal (1, 5, 14, 39, ...), A119996
diagonal (2, 8, 23, 63, ...), A180664
diagonal (2, 5, 15, 39, ...), A059840
diagonal (3, 8, 24, 63, ...), A080097
diagonal (5, 13, 39, 102, ...), A080143
diagonal (8, 21, 63, 165, ...), A080144
All the principal submatrices are invertible, and the terms in the inverses are in {-3,-2,-1,0,1,2,3}.

Examples

			Northwest corner:
1....1....2....3....5.....8....13...21
2....3....5....8...13....21....34...55
3....5....9...14...23....37....60...97
5....8...15...24...39....63...102...165
8...13...24...39...64...103...167...270
		

Crossrefs

Programs

  • Mathematica
    n = 14;
    Q = NestList[Most[Prepend[#, 0]] &, #, Length[#] - 1] &[Table[Fibonacci[k], {k, 1, n}]];
    Qt = Transpose[Q]; P1 = Qt - IdentityMatrix[n];
    P = P1[[Range[2, n], Range[1, n]]];
    F = P.Q;
    Flatten[Table[P[[i]][[k + 1 - i]], {k, 1, n - 1}, {i, 1, k}]] (* A202502 as a sequence *)
    Flatten[Table[Q[[i]][[k + 1 - i]], {k, 1, n - 1}, {i, 1, k}]] (* A202451 as a sequence *)
    Flatten[Table[F[[i]][[k + 1 - i]], {k, 1, n - 1}, {i, 1, k}]] (* A202503 as a sequence *)
    TableForm[P]  (* A202502, modified lower triangular Fibonacci array *)
    TableForm[Q]  (* A202451, upper tri. Fibonacci array *)
    TableForm[F]  (* A202503, Fibonacci fission array *)

A202462 a(n) = Sum_{j=1..n} Sum_{i=1..n} F(i,j), where F is the Fibonacci fusion array of A202453.

Original entry on oeis.org

1, 5, 21, 70, 214, 614, 1703, 4619, 12363, 32812, 86636, 228012, 598893, 1571089, 4118305, 10790194, 28262594, 74014290, 193807315, 507451415, 1328617751, 3478516440, 9107117016, 23843134680, 62422772569, 163425968669, 427856404653
Offset: 1

Views

Author

Clark Kimberling, Dec 19 2011

Keywords

Comments

Partial sums of A188516.

Crossrefs

Programs

  • GAP
    F:=Fibonacci;; List([1..30], n-> F(n+2)*F(n+3) -2*F(n+4) +n+4); # G. C. Greubel, Jul 23 2019
  • Magma
    F:=Fibonacci; [F(n+2)*F(n+3) -2*F(n+4) +n+4: n in [1..30]]; // G. C. Greubel, Jul 23 2019
    
  • Mathematica
    (* First program *)
    n = 28;
    Q = NestList[Most[Prepend[#, 0]] &, #, Length[#] - 1] &[
       Table[Fibonacci[k], {k, 1, n}]];
    P = Transpose[Q]; F = P.Q;
    a[m_] := Sum[F[[i]][[j]], {i, 1, m}, {j, 1, m}]
    Table[a[m], {m, 1, n}]  (* A202462 *)
    Table[a[m] - a[m - 1], {m, 1, n}]  (* A188516 *)
    (* Additional programs *)
    LinearRecurrence[{5,-6,-4,10,-2,-3,1},{1,5,21,70,214,614,1703},30] (* Harvey P. Dale, Jul 23 2015 *)
    With[{F=Fibonacci}, Table[F[n+2]*F[n+3] -2*F[n+4] +n+4, {n,30}]] (* G. C. Greubel, Jul 23 2019 *)
  • PARI
    vector(30, n, f=fibonacci; f(n+2)*f(n+3) -2*f(n+4) +n+4) \\ G. C. Greubel, Jul 23 2019
    
  • Sage
    f=fibonacci; [f(n+2)*f(n+3)-2*f(n+4) +n+4 for n in (1..30)] # G. C. Greubel, Jul 23 2019
    

Formula

G.f.: x*(1+2*x^2-x^3)/((1+x)*(1-3*x+x^2)*(1-x-x^2)*(1-x)^2). - R. J. Mathar, Dec 20 2011
a(n) = Fibonacci(n+2)*Fibonacci(n+3) - 2*Fibonacci(n+4) + n + 4. - G. C. Greubel, Jul 23 2019

A202452 Lower triangular Fibonacci matrix, by SW antidiagonals.

Original entry on oeis.org

1, 1, 0, 2, 1, 0, 3, 1, 0, 0, 5, 2, 1, 0, 0, 8, 3, 1, 0, 0, 0, 13, 5, 2, 1, 0, 0, 0, 21, 8, 3, 1, 0, 0, 0, 0, 34, 13, 5, 2, 1, 0, 0, 0, 0, 55, 21, 8, 3, 1, 0, 0, 0, 0, 0, 89, 34, 13, 5, 2, 1, 0, 0, 0, 0, 0, 144, 55, 21, 8, 3, 1, 0, 0, 0, 0, 0, 0
Offset: 1

Views

Author

Clark Kimberling, Dec 19 2011

Keywords

Examples

			Northwest corner:
1...0...0...0...0...0...0...0...0
1...1...0...0...0...0...0...0...0
2...1...1...0...0...0...0...0...0
3...2...1...1...0...0...0...0...0
5...3...2...1...1...0...0...0...0
		

Crossrefs

Programs

  • Mathematica
    n = 12;
    Q = NestList[Most[Prepend[#, 0]] &, #, Length[#] - 1] &[Table[Fibonacci[k], {k, 1, n}]];
    P = Transpose[Q]; F = P.Q;
    Flatten[Table[P[[i]][[k + 1 - i]], {k, 1, n}, {i, 1, k}]] (* A202451 as a sequence *)
    Flatten[Table[Q[[i]][[k + 1 - i]], {k, 1, n}, {i, 1, k}]] (* A202452 as a sequence *)
    Flatten[Table[F[[i]][[k + 1 - i]], {k, 1, n}, {i, 1, k}]] (* A202453 as a sequence *)
    TableForm[Q]  (* A202451, upper triangular Fibonacci array *)
    TableForm[P]  (* A202452, lower triangular Fibonacci array *)
    TableForm[F]  (* A202453, Fibonacci self-fusion matrix *)
    TableForm[FactorInteger[F]]

Formula

Column n consists of n-1 zeros followed by the Fibonacci sequence (1,1,2,3,5,8,...).

A202502 Modified lower triangular Fibonacci matrix, by antidiagonals.

Original entry on oeis.org

1, 0, 2, 0, 1, 3, 0, 0, 2, 5, 0, 0, 1, 3, 8, 0, 0, 0, 2, 5, 13, 0, 0, 0, 1, 3, 8, 21, 0, 0, 0, 0, 2, 5, 13, 34, 0, 0, 0, 0, 1, 3, 8, 21, 55, 0, 0, 0, 0, 0, 2, 5, 13, 34, 89, 0, 0, 0, 0, 0, 1, 3, 8, 21, 55, 144, 0, 0, 0, 0, 0, 0, 2, 5, 13, 34, 89, 233, 0, 0, 0, 0, 0, 0, 1, 3, 8, 21, 55
Offset: 1

Views

Author

Clark Kimberling, Dec 20 2011

Keywords

Comments

This matrix, P, is used to form the Fibonacci self-fission matrix as the product P*Q, where Q is the upper triangular Fibonacci matrix, A202451. To form P, delete the main diagonal of the transpose of Q.

Examples

			Northwest corner:
1...0...0...0...0...0...0...0...0
2...1...0...0...0...0...0...0...0
3...2...1...0...0...0...0...0...0
5...3...2...1...1...0...0...0...0
8...5...3...2...1...1...0...0...0
		

Crossrefs

Programs

  • Mathematica
    n = 14;
    Q = NestList[Most[Prepend[#, 0]] &, #, Length[#] - 1] &[Table[Fibonacci[k], {k, 1, n}]];
    Qt = Transpose[Q]; P1 = Qt - IdentityMatrix[n];
    P = P1[[Range[2, n], Range[1, n]]];
    F = P.Q;
    Flatten[Table[P[[i]][[k + 1 - i]], {k, 1, n - 1}, {i, 1, k}]] (* A202502 as a sequence *)
    Flatten[Table[Q[[i]][[k + 1 - i]], {k, 1, n - 1}, {i, 1, k}]] (* A202451 as a sequence *)
    Flatten[Table[F[[i]][[k + 1 - i]], {k, 1, n - 1}, {i, 1, k}]] (* A202503 as a sequence *)
    TableForm[P]  (* A202502, modified lower triangular Fibonacci matrix *)
    TableForm[Q] (* A202451, upper tri. Fibonacci matrix *)
    TableForm[F] (* A202503, Fibonacci self-fission matrix *)
Showing 1-5 of 5 results.