0,13

Each row has e.g.f. given by a truncated exponential series in exp(x)-1. For example the e.g.f. = 1 + (exp(x)-1) + (1/2)(exp(x)-1)^2 gives the sequence 1, 1, 2, 4, 8, 16... . Alternatively, first differences of columns gives triangle of Stirling numbers of 2nd kind A008277.

Triangle starts:

1;

0, 1;

0, 1, 1;

0, 1, 1, 1;

0, 1, 2, 1, 1;

0, 1, 4, 2, 1, 1;

0, 1, 8, 5, 2, 1, 1;

0, 1, 16, 14, 5, 2, 1;

...

Cf. A000110.

Sequence in context: A077042 A144903 A356266 * A108947 A338859 A152459

Adjacent sequences: A108931 A108932 A108933 * A108935 A108936 A108937

easy,nonn,tabl

Paul Boddington, Jul 20 2005

approved