A117185 Riordan array ((1-x^2)/(1+x+2x^2+x^3+x^4),x/(1+x^2)).

1, -1, 1, -2, -1, 1, 3, -3, -1, 1, 1, 4, -4, -1, 1, -4, 4, 5, -5, -1, 1, 1, -8, 8, 6, -6, -1, 1, 3, -3, -13, 13, 7, -7, -1, 1, -2, 11, -11, -19, 19, 8, -8, -1, 1, -1, 1, 24, -24, -26, 26, 9, -9, -1, 1, 1, -12, 12, 43, -43, -34, 34, 10, -10, -1, 1

Offset

0,4

Comments

Row sums are A117188. Diagonal sums are A099837. Inverse of A117184.

Links

Table of n, a(n) for n=0..65.

Example

Triangle begins
1,
-1, 1,
-2, -1, 1,
3, -3, -1, 1,
1, 4, -4, -1, 1,
-4, 4, 5, -5, -1, 1,
1, -8, 8, 6, -6, -1, 1,
3, -3, -13, 13, 7, -7, -1, 1

Crossrefs

Sequence in context: A212626 A090402 A026082 * A129181 A157694 A271187

Adjacent sequences: A117182 A117183 A117184 * A117186 A117187 A117188

Keyword

easy,sign,tabl

Author

Paul Barry, Mar 01 2006

Status

approved