OFFSET
0,4
COMMENTS
This two-dimensional array is to Pascal's triangle as sequence A004001 is to Fibonacci's sequence. The sequence gives the values for nonnegative n read by antidiagonals. For negative n, T(0, n) = 0 and T(m, n) = T(m, 0) for m > 0.
Unlike A004001 this sequence admits a simple closed form: T(1, n) = 1 if n /= 1, T(1, 1) = 2, T(m, n) = 3*2^(m-2) if m > 1, n /= 3*2^(m-2) - 2, T(m, 3*2^(m-2) - 2) = 3*2^(m-2) - 1 if m > 1.
EXAMPLE
For 0 <= m <= 3 and 0 <= n <= 5, the array of values looks like:
1,0,0,0,0,0,0
1,2,1,1,1,1,1
3,2,3,3,3,3,3
6,6,6,6,5,6,6
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Rob Arthan, Jan 06 2003
STATUS
approved