OFFSET
0,4
EXAMPLE
Triangle begins:
1;
1, 1;
2, 3, 3;
5, 8, 11, 11;
16, 24, 35, 46, 46;
62, 86, 121, 167, 213, 213;
275, 361, 482, 649, 862, 1075, 1075;
1350, 1711, 2193, 2842, 3704, 4779, 5854, 5854;
7204, 8915, 11108, 13950, 17654, 22433, 28287, 34141, 34141; ...
PROG
(PARI) T(n, k)=if(n<k || k<0, 0, if(n<=1, 1, if(n==k, T(n, k-1), if(k==0, T(n-1, 0)+T(n-1, n-1), T(n-1, k)+T(n, k-1)))))
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Paul D. Hanna, Apr 24 2007
STATUS
approved