A088969 Triangle T(n,k), read by rows, given by A000290 DELTA [1, 2, 6, 5, 11, 8, 16, 11, 21, 14, 26, 17, 31, 20, 36, ...] where DELTA is the operator defined in A084938.

1, 0, 1, 0, 1, 3, 0, 5, 20, 21, 0, 61, 287, 445, 231, 0, 1385, 7244, 13688, 11206, 3453, 0, 50521, 285295, 612556, 631862, 320159, 65271, 0, 2702765, 16195816, 38143429, 45667208, 29860381, 10300476, 1491381

Offset: 0

Author

Philippe Deléham, Oct 29 2003, Nov 07 2007

Keywords

• easy
• nonn
• tabl

Examples

			Triangle begins:
1;
0, 1;
0, 1, 3;
0, 5, 20, 21;
0, 61, 287, 445, 231;
0, 1385, 7244, 13688, 11206, 3453;
0, 50521, 285295, 612556, 631862, 320159, 65271;
0, 2702765, 16195816, 38143429, 45667208, 29860381, 10300476, 1491381;
		

Crossrefs

Cf. A000290 A000364 A000657 A084938.

Formula

Row sums : A000657; median Euler numbers (the middle of Arnold's shuttle triangle) Columns : A000007; A000364 (Euler numbers)