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.

A137227 Triangle T(n, k) = n^(n-1) * Fibonacci(k)^(n+1) - (n-1)! * (Fibonacci(k) - 1) * Sum_{j=0..n} (n*Fibonacci(k))^j/j!, with T(n, 0) = n! and T(n, 1) = n^(n-1), read by rows.

Original entry on oeis.org

1, 1, 1, 2, 2, 2, 6, 9, 9, 22, 24, 64, 64, 266, 708, 120, 625, 625, 4536, 17457, 108129, 720, 7776, 7776, 100392, 563088, 5709120, 52517688, 5040, 117649, 117649, 2739472, 22516209, 375217945, 5489293264, 92757410569, 40320, 2097152, 2097152, 89020752, 1076444064, 29566405440, 688833593904, 18867973329344, 513683908057152
Offset: 0

Views

Author

Roger L. Bagula, Mar 07 2008

Keywords

Examples

			Triangle begins as:
     1;
     1,      1;
     2,      2,      2;
     6,      9,      9,      22;
    24,     64,     64,     266,      708;
   120,    625,    625,    4536,    17457,    108129;
   720,   7776,   7776,  100392,   563088,   5709120,   52517688;
  5040, 117649, 117649, 2739472, 22516209, 375217945, 5489293264, 92757410569;
		

Crossrefs

Programs

  • Mathematica
    T[n_, k_]:= If[k==0, n!, If[k==1, n^(n-1), (1/n)*(Fibonacci[k]^(n+1)*n^n - n!*(Fibonacci[k] -1)*Sum[n^j*Fibonacci[k]^j/j!, {j,0,n}])]];
    Table[T[n, k], {n,0,10}, {k,0,n}]//Flatten (* modified by G. C. Greubel, Jan 06 2022 *)
  • Sage
    @CachedFunction
    def A137227(n,k):
        if (k==0): return factorial(n)
        elif (k==1): return n^(n-1)
        else: return (1/n)*(fibonacci(k)^(n+1)*n^n - factorial(n)*(fibonacci(k) -1)*sum((n*fibonacci(k))^j/factorial(j) for j in (0..n)))
    flatten([[A137227(n,k) for k in (0..n)] for n in (0..10)]) # G. C. Greubel, Jan 06 2022

Formula

T(n, k) = (1/n)*( n^n * Fibonacci(k)^(n+1) - n! * (Fibonacci(k) - 1) * Sum_{j=0..n} (n*Fibonacci(k))^j/j! ), with T(n, 0) = n! and T(n, 1) = n^(n-1).

Extensions

Edited by G. C. Greubel, Jan 06 2022