1,3
Table of n, a(n) for n=1..35.
H. Bottomley, Illustration of initial terms
T(n,k) = Sum_j{2j >= k} [C(2j,k)*T(n-1,j)] starting with T(1,1) = 1 and T(1,k) = 0 if k>1.
Square array starts:
1, 0, 0, 0, 0, 0, 0, 0, 0, 0, ...
2, 1, 0, 0, 0, 0, 0, 0, 0, 0, ...
8, 8, 4, 1, 0, 0, 0, 0, 0, 0, ...
80, 144, 168, 138, 80, 32, 8, 1, 0, 0, ...
...
Row sums are A001699.
Cf. A073345, A073429.
Sequence in context: A078341 A199459 A316649 * A108998 A309993 A248673
Adjacent sequences: A065326 A065327 A065328 * A065330 A065331 A065332
nonn,tabl
Henry Bottomley, Oct 29 2001
approved