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.

A348650 Even numbers in the triangle of Stirling numbers of the second kind (A008277).

Original entry on oeis.org

6, 10, 90, 350, 140, 966, 1050, 266, 28, 7770, 2646, 462, 36, 9330, 5880, 750, 145750, 246730, 11880, 86526, 1379400, 1323652, 627396, 66, 2532530, 9321312, 5715424, 1899612, 359502, 78, 788970, 49329280, 20912320, 5135130, 752752, 66066, 42355950, 210766920
Offset: 4

Views

Author

Rémy Sigrist, Oct 27 2021

Keywords

Comments

We take the even values in A008277, as they appear, with duplicates.
For any n >= 4, the n-th row has n - A007306(n) terms.

Examples

			As an irregular table, the first rows are:
     4:   6;
     5:   10;
     6:   90;
     7:   350, 140;
     8:   966, 1050, 266, 28;
     9:   7770, 2646, 462, 36;
    10:   9330, 5880, 750;
    11:   145750, 246730, 11880;
    12:   86526, 1379400, 1323652, 627396, 66;
    13:   2532530, 9321312, 5715424, 1899612, 359502, 78;
    14:   788970, 49329280, 20912320, 5135130, 752752, 66066;
    ...
		

Crossrefs

Cf. A007306, A008277, A348649 (odd numbers).

Programs

  • PARI
    row(n) = select(v -> v%2==0, vector(n, k, stirling(n, k, 2)))