A099598 Antidiagonal sums of array A099597.

1, 2, 4, 8, 19, 50, 162, 576, 2469, 11218, 59984, 331432, 2120663, 13784290, 102616622, 766648128, 6507054537, 54919451490, 523342287196, 4923469621256, 52040350449307, 539901936037202, 6268123599148282

Offset: 0

Author

Ralf Stephan, Oct 28 2004

Keywords

• nonn

Formula

a(n)=sum{k=0..n, C(n,k)*(floor(k/2)!)^2}; a(n)=sum{k=0..n, sum{j=0..n-k, C(n-k,j)C(k,j)j!^2}}; - Paul Barry, May 26 2007