A278072 Riordan array(1/(1+x), (1-sqrt(1-4*x))/(2*x)).

1, -1, 1, 1, 1, 1, -1, 4, 3, 1, 1, 10, 11, 5, 1, -1, 32, 37, 22, 7, 1, 1, 100, 128, 88, 37, 9, 1, -1, 329, 444, 341, 171, 56, 11, 1, 1, 1101, 1558, 1297, 739, 294, 79, 13, 1, -1, 3761, 5514, 4891, 3069, 1406, 465, 106, 15, 1, 1, 13035, 19680, 18365, 12435, 6346, 2442, 692, 137, 17, 1

Offset: 0

Author

Peter Luschny, Nov 22 2016

Keywords

• sign
• tabl

Examples

			[   1]
[  -1,   1]
[   1,   1,   1]
[  -1,   4,   3,   1]
[   1,  10,  11,   5,   1]
[  -1,  32,  37,  22,   7,  1]
[   1, 100, 128,  88,  37,  9,  1]
[  -1, 329, 444, 341, 171, 56, 11, 1]
		

Crossrefs

Cf. A033297, A084849.

Programs

Mathematica

(* The function RiordanArray is defined in A256893. *)
RiordanArray[1/(1+#)&, (1-Sqrt[1-4#])/(2#)&, 11] // Flatten (* Jean-François Alcover, Jul 16 2019 *)

Sage

# uses[riordan_array from A256893]
riordan_array(1/(1+x), (1-sqrt(1-4*x))/(2*x), 8)