A114283 Sequence array for binomial transform of Jacobsthal numbers A001045(n+1).

1, 2, 1, 6, 2, 1, 18, 6, 2, 1, 54, 18, 6, 2, 1, 162, 54, 18, 6, 2, 1, 486, 162, 54, 18, 6, 2, 1, 1458, 486, 162, 54, 18, 6, 2, 1, 4374, 1458, 486, 162, 54, 18, 6, 2, 1, 13122, 4374, 1458, 486, 162, 54, 18, 6, 2, 1, 39366, 13122, 4374, 1458, 486, 162, 54, 18, 6, 2, 1

Offset: 0

Author

Paul Barry, Nov 20 2005

Keywords

• easy
• nonn
• tabl

Comments

Sequence array for A025192. Row sums are 3^n, A000244. Diagonal sums are A015518(n+1). Inverse is A114284.

Examples

			Triangle begins
1;
2,1;
6,2,1;
18,6,2,1;
54,18,6,2,1;
162,54,18,6,2,1;
		

Links

• Reinhard Zumkeller, Rows n = 0..120 of triangle, flattened

Programs

Haskell

a114283 n k = a114283_tabl !! n !! k
a114283_row n = a114283_tabl !! n
a114283_tabl = iterate
   (\row -> (sum $ zipWith (+) row $ reverse row) : row) [1]
-- Reinhard Zumkeller, Nov 27 2012

Formula

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