A114284 Riordan array ((1-3*x)/(1-x), x).

1, -2, 1, -2, -2, 1, -2, -2, -2, 1, -2, -2, -2, -2, 1, -2, -2, -2, -2, -2, 1, -2, -2, -2, -2, -2, -2, 1, -2, -2, -2, -2, -2, -2, -2, 1, -2, -2, -2, -2, -2, -2, -2, -2, 1, -2, -2, -2, -2, -2, -2, -2, -2, -2, 1, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, 1

Offset: 0

Author

Paul Barry, Nov 20 2005

Keywords

• easy
• sign
• tabl

Comments

Inverse of A114283. Row sums are 1-2n. Diagonal sums are A114285. Sequence array of 3*0^n-2.

Examples

			Triangle begins:
  1;
  -2,1;
  -2,-2,1;
  -2,-2,-2,1;
  -2,-2,-2,-2,1;
		

Links

• Michael De Vlieger, Table of n, a(n) for n = 0..1000
• Ângela Mestre, José Agapito, Square Matrices Generated by Sequences of Riordan Arrays, J. Int. Seq., Vol. 22 (2019), Article 19.8.4.

Programs

Mathematica

Table[-2 - 3 Floor[1/2 (-1 + Sqrt[1 + 8 x])] + 3 Floor[1/2 (-1 + Sqrt[9 + 8 x])], {x, 0, 65}] (* Jackson Xier, Oct 07 2011 *)

Formula

T(n, k) = if(k<=n, 3*0^(n-k)-2, 0).

a(n) = -3*floor((1/2)*sqrt(8*n+1)-1/2)+3*floor((1/2)*sqrt(8*n+9)-1/2)-2. - Jackson Xier, Oct 07 2011