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.

A137650 Triangle read by rows, A008277 * A000012.

Original entry on oeis.org

1, 2, 1, 5, 4, 1, 15, 14, 7, 1, 52, 51, 36, 11, 1, 203, 202, 171, 81, 16, 1, 877, 876, 813, 512, 162, 22, 1, 4140, 4139, 4012, 3046, 1345, 295, 29, 1, 21147, 21146, 20891, 17866, 10096, 3145, 499, 37, 1, 115975, 115974, 115463
Offset: 1

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Author

Gary W. Adamson, Feb 01 2008

Keywords

Comments

Left column = Bell numbers (A000110) starting (1, 2, 5, 15, 52, 203, ...). Row sums = A005493(n+1): (1, 3, 10, 37, 151, 674, ...).
Corresponding to the generalized Stirling number triangle of first kind A049444. - Peter Luschny, Sep 18 2011

Examples

			First few rows of the triangle are
    1;
    2,   1;
    5,   4,   1;
   15,  14,   7,   1;
   52,  51,  36,  11,   1;
  203, 202, 171,  81,  16,   1;
  877, 876, 813, 512, 162,  22,   1;
  ...
		

Crossrefs

A similar triangle is A133611.

Programs

  • Maple
    A137650_row := proc(n) local k,i;
    add(add(combinat[stirling2](n, n-i), i=0..k)*x^(n-k-1),k=0..n-1);
    seq(coeff(%,x,k),k=0..n-1) end:
    seq(print(A137650_row(n)),n=1..7); # Peter Luschny, Sep 18 2011
  • Mathematica
    row[n_] := Table[StirlingS2[n, k], {k, 0, n}] // Reverse // Accumulate // Reverse // Rest;
    Array[row, 10] // Flatten (* Jean-François Alcover, Dec 07 2019 *)

Formula

A008277 * A000012 as infinite lower triangular matrices. Partial sums of A008277 rows starting from the right.