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.

A081114 Triangle read by rows: T(n,k) = n*T(n-1,k) + n - k starting at T(n,n)=0.

Original entry on oeis.org

0, 1, 0, 4, 1, 0, 15, 5, 1, 0, 64, 23, 6, 1, 0, 325, 119, 33, 7, 1, 0, 1956, 719, 202, 45, 8, 1, 0, 13699, 5039, 1419, 319, 59, 9, 1, 0, 109600, 40319, 11358, 2557, 476, 75, 10, 1, 0, 986409, 362879, 102229, 23019, 4289, 679, 93, 11, 1, 0, 9864100, 3628799, 1022298, 230197, 42896, 6795, 934, 113, 12, 1, 0
Offset: 0

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Author

Henry Bottomley, Apr 16 2003

Keywords

Comments

Taking the triangle into negative values of n and k would produce results close to (k+1)*e*n! - 1, i.e., one less than multiples of A000522 for nonnegative n.

Examples

			Triangle begins
    0;
    1,   0;
    4,   1,  0;
   15,   5,  1, 0;
   64,  23,  6, 1, 0;
  325, 119, 33, 7, 1, 0;
		

Crossrefs

Columns include A007526 and A033312.

Programs

  • PARI
    T(n,k) = if (k==n, 0, n*T(n-1,k) + n - k);
    tabl(nn) = {for (n=0, nn, for (k=0, n, print1(T(n, k), ", ");); print(););} \\ Michel Marcus, Jun 16 2019

Formula

For k > 0, T(n, k) = ceiling((A001339(k-1)/(k-1)! - (k-1)*e) *n! - 1) where A001339(k-1) = ceiling((k-1)!*(k-1)*e) for k > 1.
T(n, 0) = floor(e*n! - 1) for n > 0; T(n, 1) = n! - 1. T(n, n)=0; T(n, n-1) = n+2; T(n, n-2) = n^2 + 3*n + 5 = A027688(n+1).

Extensions

More terms from Michel Marcus, Jun 16 2019