A166279 Triangle, read by rows: T(0,0) = 1, T(n,k) = T(n-1,k-1) (mod 2) + T(n-1,k) (mod 2), T(n,k) = 0 if k < 0 or k > n.

1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 0, 0, 1, 1, 1, 2, 1, 0, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 1, 0, 0, 0, 0, 0, 1, 2, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 1, 0, 0, 0, 1, 2, 2, 2, 1

Offset: 0

Author

Gerald McGarvey, Oct 10 2009

Keywords

• easy
• nonn
• tabl

Examples

			Triangle begins:
1,
1,1,
1,2,1,
1,1,1,1,
1,2,2,2,1,
1,1,0,0,1,1,
1,2,1,0,1,2,1,
1,1,1,1,1,1,1,1,
1,2,2,2,2,2,2,2,1,
1,1,0,0,0,0,0,0,1,1,
1,2,1,0,0,0,0,0,1,2,1,
1,1,1,1,0,0,0,0,1,1,1,1,
1,2,2,2,1,0,0,0,1,2,2,2,1,
1,1,0,0,1,1,0,0,1,1,0,0,1,1,
1,2,1,0,1,2,1,0,1,2,1,0,1,2,1,
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,1,
1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1
		

Crossrefs

A007318 (Pascal's triangle), A047999 (Sierpinski's triangle, Pascal's triangle mod 2).

Programs

PARI

p = 2; s = 13; T=matrix(s,s); T[1,1]=1; for(n=2,s,T[n,1]=1;for(k=2,n,T[n,k]=T[n-1,k-1]%p+T[n-1,k]%p)); for(n=1,s,for(k=1,n,print1(T[n,k],", ")))