A216219 - OEIS

A216219

Square array T, read by antidiagonals: T(n,k) = 0 if n-k>=5 or if k-n>=5, T(4,0) = T(3,0) = T(2,0) = T(1,0) = T(0,0) = T(0,1) = T(0,2) = T(0,3) = T(0,4) = 1, T(n,k) = T(n-1,k) + T(n,k-1).

1, 1, 1, 1, 2, 1, 1, 3, 3, 1, 1, 4, 6, 4, 1, 0, 5, 10, 10, 5, 0, 0, 5, 15, 20, 15, 5, 0, 0, 0, 20, 35, 35, 20, 0, 0, 0, 0, 20, 55, 70, 55, 20, 0, 0, 0, 0, 0, 75, 125, 125, 75, 0, 0, 0, 0, 0, 0, 75, 200, 250, 200

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OFFSET

0,5

LINKS

Table of n, a(n) for n=0..61.

FORMULA

T(n,n) = A147748(n).

T(n+1,n) = T(n,n+1) = A081567(n).

T(n+2,n) = T(n,n+2) = A039717(n+1).

T(n+3,n) = T(n+4,n) = T(n,n+3) = T(n,n+4) = A030191(n).

Sum_{k, 0<=k<=n} T(n-k,k) = A068913(4,n) = A216212(n).

EXAMPLE