A129685 Exponential Riordan array [1-x^2/2, x].

1, 0, 1, -1, 0, 1, 0, -3, 0, 1, 0, 0, -6, 0, 1, 0, 0, 0, -10, 0, 1, 0, 0, 0, 0, -15, 0, 1, 0, 0, 0, 0, 0, -21, 0, 1, 0, 0, 0, 0, 0, 0, -28, 0, 1, 0, 0, 0, 0, 0, 0, 0, -36, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, -45, 0, 1

Offset: 0

Author

Paul Barry, Apr 28 2007

Keywords

• easy
• sign
• tabl

Examples

			Triangle begins
1,
0, 1,
-1, 0, 1,
0, -3, 0, 1,
0, 0, -6, 0, 1,
0, 0, 0, -10, 0, 1,
0, 0, 0, 0, -15, 0, 1,
0, 0, 0, 0, 0, -21, 0, 1,
0, 0, 0, 0, 0, 0, -28, 0, 1,
0, 0, 0, 0, 0, 0, 0, -36, 0, 1,
0, 0, 0, 0, 0, 0, 0, 0, -45, 0, 1
		

Crossrefs

Inverse of A129684. Row sums are A080956.

Programs

Mathematica

(* The function RiordanArray is defined in A256893. *)
RiordanArray[1 - #^2/2&, #&, 11, True] // Flatten (* Jean-François Alcover, Jul 19 2019 *)