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.

A144499 Column 3 of array in A144502.

Original entry on oeis.org

1, 16, 155, 1633, 19714, 272501, 4269271, 74971240, 1460701853, 31295474659, 731658123646, 18541725927671, 506405138998225, 14830681754924608, 463675143369795659, 15415347314972132761, 543080592733655070466, 20211128647048824421085, 792340775489805581958823
Offset: 0

Views

Author

David Applegate and N. J. A. Sloane, Dec 13 2008

Keywords

Crossrefs

Cf. A144502.

Programs

  • Magma
    [n le 2 select (16)^(n-1) else ((12*(n-1)^2+8*(n-1)+3)*Self(n-1) + (6*(n-1)+1)*Self(n-2) )/(6*(n-1) -5): n in [1..30]]; // G. C. Greubel, Oct 07 2023
    
  • Mathematica
    a[n_]:= a[n]= If[n<2, 16^n, ((12*n^2+8*n+3)*a[n-1] +(6*n+1)*a[n-2])/(6*n-5)];
    Table[a[n], {n, 0, 30}] (* G. C. Greubel, Oct 07 2023 *)
  • SageMath
    @CachedFunction
    def a(n): # a = A144499
        if n<2: return (16)^n
        else: return ((12*n^2+8*n+3)*a(n-1) +(6*n+1)*a(n-2))/(6*n-5)
    [a(n) for n in range(31)] # G. C. Greubel, Oct 07 2023

Formula

(6*n-5)*a(n) = (12*n^2 +8*n +3)*a(n-1) + (6*n+1)*a(n-2). - G. C. Greubel, Oct 07 2023