A164984 Odd (Jacobsthal) triangle.

1, 1, 1, 3, 3, 1, 5, 9, 5, 1, 11, 23, 19, 7, 1, 21, 57, 61, 33, 9, 1, 43, 135, 179, 127, 51, 11, 1, 85, 313, 493, 433, 229, 73, 13, 1, 171, 711, 1299, 1359, 891, 375, 99, 15, 1, 341, 1593, 3309, 4017, 3141, 1641, 573, 129, 17, 1

Offset: 1

Author

Mark Dols, Sep 03 2009, Sep 06 2009

Keywords

• nonn
• tabl

Comments

Alternate diagonal sums give A008619.

Diagonals sums give A097076. - Philippe Deléham, Oct 13 2013

Examples

			1
1,1
3,3,1
5,9,5,1
11,23,19,7,1
21,57,61,33,9,1
Pascal-like triangle based on a right-triangular sum (with the top multiplied by 2): For n=13 a(13)=2*a(3)+a(5)+a(8)+a(9)= 2+3+9+5=19.
		

Crossrefs

Cf. A164981, A001045, A005408, A015518 (row sums), A008619

Cf. A008288, A007318.

Formula

Excel formula: C6=2*C4+C5+B5+B4 with C5=a(1)=1 and C6=a(2)

T(n,k) = T(n-1,k) + T(n-1,k-1) + 2*T(n-2,k) + T(n-2,k-1). - Philippe Deléham, Oct 13 2013