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.

A027952 a(n) = T(2n,n+4), T given by A027948.

Original entry on oeis.org

1, 10, 231, 2300, 14820, 72905, 298925, 1077748, 3540913, 10871723, 31775031, 89633545, 246575109, 666605513, 1781049298, 4721874921, 12456394685, 32758238316, 85985810716, 225446971141, 590714939822, 1547211717890, 4051642877482, 10608719012366, 27775885869046
Offset: 4

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Crossrefs

Programs

  • GAP
    Concatenation([1], List([5..40], n-> Fibonacci(2*n+10) -(138600 +133530*n +63999*n^2 + 20286*n^3 +5929*n^4 +616*n^6 -96*n^7 +16*n^8)/2520) ); # G. C. Greubel, Sep 29 2019
  • Magma
    [1] cat [Fibonacci(2*n+10) -(138600 +133530*n +63999*n^2 + 20286*n^3 +5929*n^4 +616*n^6 -96*n^7 +16*n^8)/2520: n in [5..40]]; // G. C. Greubel, Sep 29 2019
    
  • Maple
    with(combinat); seq(`if`(n=4,1, fibonacci(2*n+10) -(138600 +133530*n +63999*n^2 + 20286*n^3 +5929*n^4 +616*n^6 -96*n^7 +16*n^8)/2520), n=4..40); # G. C. Greubel, Sep 29 2019
  • Mathematica
    Table[If[n==4, 1, Fibonacci[2*n+10] - (138600 +133530*n +63999*n^2 + 20286*n^3 +5929*n^4 +616*n^6 -96*n^7 +16*n^8)/2520], {n, 4, 40}] (* G. C. Greubel, Sep 29 2019 *)
  • PARI
    vector(40, n, my(m=n+3); if(m==4, 1, fibonacci(2*m+10) -(138600 +133530*m +63999*m^2 + 20286*m^3 +5929*m^4 +616*m^6 -96*m^7 +16*m^8)/2520) ) \\ G. C. Greubel, Sep 29 2019
    
  • Sage
    [1]+[fibonacci(2*n+10) -(138600 +133530*n +63999*n^2 + 20286*n^3 +5929*n^4 +616*n^6 -96*n^7 +16*n^8)/2520 for n in (5..40)] # G. C. Greubel, Sep 29 2019
    

Formula

From G. C. Greubel, Sep 29 2019: (Start)
a(n) = Sum_{j=0..n-3} binomial(2*n-j, j+9), with a(4) = 1.
a(n) = Fibonacci(2*n+10) - (138600 +133530*n +63999*n^2 + 20286*n^3 + 5929*n^4 + 616*n^6 - 96*n^7 + 16*n^8)/2520.
G.f.: x^4*(1 - 2*x + 175*x^2 - 33*x^3 + 408*x^4 - 614*x^5 + 587*x^6 - 414*x^7 + 201*x^8 - 64*x^9 + 12*x^10 - x^11)/((1-x)^9*(1-3*x+x^2)). (End)

Extensions

Terms a(23) onward added by G. C. Greubel, Sep 29 2019