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.

A174640 A triangular sequence:t(n,m)=A033306(n,m)-A033306(n,0)+1.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 6, 10, 6, 1, 1, 24, 49, 49, 24, 1, 1, 110, 248, 298, 248, 110, 1, 1, 545, 1308, 1749, 1749, 1308, 545, 1, 1, 2877, 7229, 10421, 11611, 10421, 7229, 2877, 1, 1, 16114, 41998, 64114, 77134, 77134, 64114, 41998, 16114, 1, 1, 95496
Offset: 0

Views

Author

Roger L. Bagula, Mar 25 2010

Keywords

Comments

Row sums are:
1, 2, 3, 6, 24, 148, 1016, 7206, 52667, 398722, 3137084,...

Examples

			{1},
{1, 1},
{1, 1, 1},
{1, 2, 2, 1},
{1, 6, 10, 6, 1},
{1, 24, 49, 49, 24, 1},
{1, 110, 248, 298, 248, 110, 1},
{1, 545, 1308, 1749, 1749, 1308, 545, 1},
{1, 2877, 7229, 10421, 11611, 10421, 7229, 2877, 1},
{1, 16114, 41998, 64114, 77134, 77134, 64114, 41998, 16114, 1},
{1, 95496, 256626, 410226, 523476, 565434, 523476, 410226, 256626, 95496, 1}
		

References

  • This notebook downloaded from https://mathworld.wolfram.com/notebooks/Combinatorics/BellNumber.nb.
  • J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 80.

Crossrefs

Programs

  • Mathematica
    b[0] := 1;
    b[n_] := b[n] = Total[Table[b[k]Binomial[n - 1, k], {k, 0, n - 1}]];
    a = b /@ Range[0, 70];
    t[n_, m_] := Binomial[n, m]*a[[m + 1]]*a[[n - m + 1]];
    Table[Table[t[n, m] - t[n, 0] + 1, {m, 0, n}], {n, 0, 10}];
    Flatten[%]

Formula

t(n,m)=A033306(n,m)-A033306(n,0)+1