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

0,1

Comments

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

Links

Table of n, a(n) for n=0..104.

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).

Example

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

Crossrefs

Sequence in context: A115952 A115524 A370122 * A271047 A054525 A174852

Adjacent sequences: A117195 A117196 A117197 * A117199 A117200 A117201

Keyword

easy,nonn,tabl

Author

Paul Barry, Mar 02 2006

Status

approved