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A071164
Square array read by antidiagonals of T(n,k)=T(n-1,k-n)+T(n-k,k-1) starting with T(n,k)=0 if either n or k are negative but with T(0,0)=1.
1
1, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 2, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
OFFSET
0,5
FORMULA
All values are 0 or 2 except T(0, 0)=1. Final positive values in n-th row and column occur at T(n, n(n+1)/2) and T(n(n+1)/2, n).
EXAMPLE
Rows start: 1,0,0,...; 0,2,0,0,...; 0,0,0,2,0,0,...; 0,0,2,0,0,0,2,0,0,...; 0,0,0,0,0,0,2,0,0,0,2,0,0,...; 0,0,0,0,0,0,0,0,0,0,0,2,0,0,0,2,0,0,...; 0,0,0,2,2,0,0,0,0,0,0,0,0,0,0,0,0,2,0,0,0,2,0,0,...; etc.
CROSSREFS
Cf. A071165 for row and column sums. A054431 for a similar formula with a different result.
Sequence in context: A204853 A303709 A185778 * A027345 A328959 A086080
KEYWORD
nonn,tabl
AUTHOR
Henry Bottomley, May 14 2002
STATUS
approved