A144155 Bell convolution triangle, T(n,k) = A000110(n-k)*A000110(k).

1, 1, 1, 2, 1, 2, 5, 2, 2, 5, 15, 5, 4, 5, 15, 52, 15, 10, 10, 15, 52, 203, 52, 30, 25, 30, 52, 203, 877, 203, 104, 75, 75, 104, 203, 877, 4140, 877, 406, 260, 225, 260, 406, 877, 4140, 21147, 4140, 1754, 1015, 780, 780, 1015, 1754, 4140, 21147

Offset: 0

Author

Gary W. Adamson, Sep 12 2008

Keywords

• nonn
• tabl

Comments

Row sums = A014322: (1, 2, 5, 14, 44, 154,...) the Bell numbers convolved with themselves.

Examples

			First few rows of the triangle =
1;
1, 1;
2, 1, 2;
5, 2, 2, 5;
15, 5, 4, 5, 15;
52, 15, 10, 10, 15, 52;
203, 52, 30, 25, 30, 52, 203;
...
Row 3 = (5, 2, 2, 5) = termwise products of (1, 1, 2, 5) and (5, 2, 1, 1) = (5*1, 1*2, 2*1, 5*1).
		

Crossrefs

A000110, Cf. A014322

Formula

Triangle read by rows, T(n,k) = A000110(n-k)*A000110(k)

Extensions

More terms from Philippe Deléham, Jan 29 2012