OFFSET
0,13
FORMULA
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.
EXAMPLE
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;
...
CROSSREFS
KEYWORD
AUTHOR
Paul Boddington, Jul 20 2005
STATUS
approved