A117198 Generalized Riordan array (1,x)+(x,x^2)+(x^2,x^3).

1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1

Offset: 0

Author

Paul Barry, Mar 02 2006

Keywords

• easy
• nonn
• tabl

Comments

Row sums are A083039. Diagonal sums are A117199. Inverse is A117200.

Examples

			Triangle begins
1,
1, 1,
1, 0, 1,
0, 1, 0, 1,
0, 0, 0, 0, 1,
0, 1, 1, 0, 0, 1,
0, 0, 0, 0, 0, 0, 1,
0, 0, 0, 1, 0, 0, 0, 1,
0, 0, 1, 0, 0, 0, 0, 0, 1,
0, 0, 0, 0, 1, 0, 0, 0, 0, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
		

Formula

Number triangle T(n,k)=if(n=k,1,0) OR if(n=2k+1,1,0) OR if(n=3k+2,1,0).