A102427 Triangle based on downward diagonals of A102426.

1, 1, 1, 1, 3, 2, 1, 5, 4, 1, 1, 7, 6, 6, 3, 1, 9, 8, 15, 10, 1, 1, 11, 10, 28, 21, 10, 4, 1, 13, 12, 45, 36, 35, 20, 1, 1, 15, 14, 66, 55, 84, 56, 15, 5, 1, 17, 16, 91, 78, 165, 120, 70, 35, 1, 1, 19, 18, 120, 105, 286, 220, 210, 126, 21, 6

Offset: 0

Author

Russell Walsmith, Jan 11 2005

Keywords

• easy
• nonn
• tabl

Crossrefs

Cf. A011973, A102426, A102428, A102429.

Formula

T(n, k)=if(k<=n, binomial(floor((2n-k+2)/2)+n-k, floor((2n-k+1)/2)-n+k), 0) - Paul Barry, Jun 22 2005

Extensions

Corrected and extended by Paul Barry, Jun 22 2005