A096626 Triangle (read by rows) where the number of row entries increases by steps of 2 and the entries are stacked in a rectangular fashion. The left end entry = 1 if row number is even, the right end entry = 1 if row number is odd. Rest of entries = sum of the entry directly above in the previous row plus the two entries (when present) in the previous row that are either to the left (if the current row number is even) or to the right (if odd).

1, 1, 1, 1, 2, 3, 2, 1, 1, 1, 2, 5, 7, 6, 4, 2, 3, 8, 14, 18, 17, 12, 6, 2, 1, 1, 3, 11, 25, 40, 49, 47, 35, 20, 9, 3, 4, 15, 39, 76, 114, 136, 131, 102, 64, 32, 12, 3, 1, 1, 4, 19, 58, 130, 229, 326, 381, 369, 297, 198, 108, 47, 16, 4, 5, 24, 81, 207, 417, 685, 936, 1076, 1047, 864

Offset

1,5

Comments

The row sums are powers of 3 (A000244).

Links

Table of n, a(n) for n=1..74.

Example

........................1........................
....................1...1...1....................
................2...3...2...1...1................
............1...2...5...7...6...4...2............
........3...8..14..18..17..12...6...2...1........
.....1..3..11..25..40..49..47..35..20...9..3.....
..4.15.39..76.114.136.131.102..64..32..12..3..1..
1.4.19.58.130.229.326.381.369.297.198.108.47.16.4

Crossrefs

Cf. A000244.

Sequence in context: A171457 A129385 A217983 * A083279 A306239 A159455

Adjacent sequences: A096623 A096624 A096625 * A096627 A096628 A096629

Keyword

nonn,tabf

Author

Gerald McGarvey, Aug 14 2004

Status

approved