OFFSET
0,8
EXAMPLE
Triangle begins:
1;
1, 1;
1, 1, 1;
1, 2, 1, 1;
1, 3, 3, 1, 1;
1, 6, 6, 4, 1, 1;
1, 12, 15, 10, 5, 1, 1;
1, 27, 40, 29, 15, 6, 1, 1;
1, 67, 113, 93, 49, 21, 7, 1, 1;
1, 180, 348, 310, 180, 76, 28, 8, 1, 1;
1, 528, 1148, 1106, 685, 311, 111, 36, 9, 1, 1;
1, 1676, 4045, 4205, 2748, 1322, 497, 155, 45, 10, 1, 1;
1, 5721, 15203, 16912, 11683, 5858, 2323, 750, 209, 55, 11, 1, 1;
1, 20924, 60710, 71858, 52262, 27349, 11230, 3809, 1083, 274, 66, 12, 1, 1; ...
ILLUSTRATE RECURRENCE:
T(6,1) = T(5,1) + T(5,2) = 6 + 6 = 12;
T(7,2) = T(6,2) + 2*T(6,3) + T(6,4) = 6 + 2*4 + 1 = 15;
T(8,3) = T(7,3) + 3*T(7,4) + 3*T(7,5) + T(7,6) = 29 + 3*15 + 3*6 + 1 = 93.
Note that column 1 equals A122889: [1,1,2,3,6,12,27,67,180,528,...]
which is the antidiagonal sums of triangle A122888.
RELATED TRIANGLE A122888 begins:
1;
1, 1;
1, 2, 2, 1;
1, 3, 6, 9, 10, 8, 4, 1;
1, 4, 12, 30, 64, 118, 188, 258, 302, 298, 244, 162, 84, 32, 8, 1;
1, 5, 20, 70, 220, 630, 1656, 4014, 8994, 18654, 35832, 63750,...;
1, 6, 30, 135, 560, 2170, 7916, 27326, 89582, 279622, 832680,...;
1, 7, 42, 231, 1190, 5810, 27076, 121023, 520626, 2161158,...;
1, 8, 56, 364, 2240, 13188, 74760, 409836, 2179556, 11271436,...; ...
in which the g.f. of row n equals the n-th iteration of (x+x^2).
PROG
(PARI) T(n, k)=if(n<k || k<0, 0, if(n==k, 1, sum(j=0, k, binomial(k, j)*T(n-1, j+k))))
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Paul D. Hanna, Dec 23 2008
STATUS
approved