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 1-4 of 4 results.

A024595 a(n) = s(1)*t(n) + s(2)*t(n-1) + ... + s(k)*t(n+1-k), where k = floor((n+1)/2), s = (F(2), F(3), ...), t = A023533.

Original entry on oeis.org

1, 0, 0, 1, 2, 3, 5, 0, 0, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1598, 2586, 4184, 6770, 10954, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181, 6765, 10946, 17711, 28658, 46370, 75028, 121398, 196426
Offset: 1

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Crossrefs

Programs

  • Magma
    A023533:= func< n | Binomial(Floor((6*n-1)^(1/3)) +2, 3) ne n select 0 else 1 >;
    [(&+[Fibonacci(k+1)*A023533(n-k+1): k in [1..Floor((n+1)/2)]]): n in [1..100]]; // G. C. Greubel, Jul 14 2022
    
  • Mathematica
    A023533[n_]:= If[Binomial[Floor[Surd[6*n-1, 3]] +2, 3] != n, 0, 1];
    A024595[n_]:= A024595[n]= Sum[Fibonacci[k+1]*A023533[n+1-k], {k, Floor[(n+1)/2]}];
    Table[A024595[n], {n,100}] (* G. C. Greubel, Jul 14 2022 *)
  • SageMath
    def A023533(n):
        if binomial( floor( (6*n-1)^(1/3) ) +2, 3) != n: return 0
        else: return 1
    [sum(fibonacci(k+1)*A023533(n-k+1) for k in (1..((n+1)//2))) for n in (1..100)] # G. C. Greubel, Jul 14 2022

Formula

a(n) = Sum_{k=1..floor((n+1)/2)} Fibonacci(k+1)*A023533(n-k+1).

A025109 a(n) = s(1)*t(n) + s(2)*t(n-1) + ... + s(k)*t(n-k+1), where k = floor(n/2), s = (F(2), F(3), F(4), ...), t = A023533.

Original entry on oeis.org

0, 0, 1, 2, 3, 0, 0, 0, 1, 2, 3, 5, 8, 13, 21, 34, 55, 0, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1598, 2586, 4184, 6770, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181, 6765, 10946, 17711, 28658, 46370, 75028, 121398, 196426, 317824, 514250
Offset: 2

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Author

Keywords

Crossrefs

Programs

  • Magma
    A023533:= func< n | Binomial(Floor((6*n-1)^(1/3)) +2, 3) ne n select 0 else 1 >;
    [(&+[Fibonacci(k+1)*A023533(n-k+1): k in [1..Floor(n/2)]]): n in [2..100]]; // G. C. Greubel, Jul 14 2022
    
  • Mathematica
    A023533[n_]:= If[Binomial[Floor[Surd[6*n-1, 3]] + 2, 3] != n, 0, 1];
    A025109[n_]:= A025109[n]= Sum[Fibonacci[k+1]*A023533[n+1-k], {k, Floor[n/2]}];
    Table[A025109[n], {n, 2, 100}] (* G. C. Greubel, Jul 14 2022 *)
  • SageMath
    def A023533(n):
        if binomial( floor( (6*n-1)^(1/3) ) +2, 3) != n: return 0
        else: return 1
    [sum(fibonacci(k+1)*A023533(n-k+1) for k in (1..(n//2))) for n in (2..100)] # G. C. Greubel, Jul 14 2022

Formula

a(n) = Sum_{k=1..floor(n/2)} Fibonacci(k+1)*A023533(n-k+1).

Extensions

a(36) corrected by Sean A. Irvine, Aug 07 2019
Offset corrected by G. C. Greubel, Jul 14 2022

A023655 Convolution of (F(2), F(3), F(4), ...) and A023533.

Original entry on oeis.org

1, 2, 3, 6, 10, 16, 26, 42, 68, 111, 180, 291, 471, 762, 1233, 1995, 3228, 5223, 8451, 13675, 22127, 35802, 57929, 93731, 151660, 245391, 397051, 642442, 1039493, 1681935, 2721428, 4403363, 7124791
Offset: 1

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Crossrefs

Essentially the same as A023613.

Programs

  • Magma
    A023533:= func< n | Binomial(Floor((6*n-1)^(1/3)) +2, 3) ne n select 0 else 1 >;
    [(&+[Fibonacci(k+2)*A023533(n-k): k in [0..n-1]]): n in [1..50]]; // G. C. Greubel, Jul 16 2022
    
  • Mathematica
    Table[Sum[Fibonacci[m+1 -Binomial[j+3,3]], {j,0,n}], {n,0,5}, {m, Binomial[n+3,3] +1, Binomial[n+4,3]}]//Flatten (* G. C. Greubel, Jul 16 2022 *)
  • SageMath
    def A023655(n, k): return sum(fibonacci(k+1-binomial(j+3,3)) for j in (0..n))
    flatten([[A023655(n, k) for k in (binomial(n+3,3)+1..binomial(n+4,3))] for n in (0..5)]) # G. C. Greubel, Jul 16 2022

Formula

a(n) = Sum_{k=0..n-1} Fibonacci(k+2) * A023533(n-k), n >= 1. - G. C. Greubel, Jul 16 2022

A023671 Convolution of A023533 and A014306.

Original entry on oeis.org

0, 1, 1, 0, 2, 2, 1, 2, 2, 1, 3, 3, 1, 3, 3, 3, 3, 3, 2, 2, 4, 4, 2, 4, 4, 4, 4, 4, 2, 4, 4, 4, 4, 4, 3, 5, 5, 3, 4, 5, 5, 5, 5, 3, 5, 5, 5, 5, 5, 5, 5, 5, 5, 3, 5, 4, 6, 6, 4, 6, 6, 6, 6, 6, 4, 6, 6, 6, 5, 6, 6, 6, 6, 6, 4, 6, 6, 6, 6, 6, 6, 6, 6, 5, 7, 7, 5, 7, 7, 5
Offset: 1

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Programs

Formula

a(n) = Sum_{j=1..n} A023533(n-j+1)*A014306(j).
From G. C. Greubel, Jul 18 2022: (Start)
a(n) = Sum_{j=1..n} A023533(n-j+1)*(1 - A023533(j)).
a(n) = A056556(n) - A023670(n). (End)
Showing 1-4 of 4 results.