A096601 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 end entries are set to 1. Rest of entries are set to the sum of the entry directly above in the previous row plus the entry (if present) in the previous row that is either to the left (if the current row number is even) or to the right (if odd).

1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 3, 4, 3, 2, 1, 1, 2, 4, 7, 7, 5, 3, 1, 1, 1, 1, 3, 6, 11, 14, 12, 8, 4, 2, 1, 1, 2, 4, 9, 17, 25, 26, 20, 12, 6, 3, 1, 1, 1, 1, 3, 6, 13, 26, 42, 51, 46, 32, 18, 9, 4, 2, 1, 1, 2, 4, 9, 19, 39, 68, 93, 97, 78, 50, 27, 13, 6, 3, 1, 1

Offset

1,6

Comments

The row sums are 2^n-1 (A000225). Shares many entries with A027926., e.g. the 'central column' (and greatest numbers in the rows) is A027988 (Greatest number in row n of array T given by A027926.)

Links

Table of n, a(n) for n=1..81.

Example

........................1........................
.....................1..1..1.....................
..................1..2..2..1..1..................
...............1..1..3..4..3..2..1...............
............1..2..4..7..7..5..3..1..1............
.........1..1..3..6.11.14.12..8..4..2..1.........
......1..2..4..9.17.25.26.20.12..6..3..1..1......
...1..1..3..6.13.26.42.51.46.32.18..9..4..2..1...
1..2..4..9.19.39.68.93.97.78.50.27.13..6..3..1..1

Crossrefs

Cf. A000225, A027926, A027988.

Sequence in context: A175025 A076899 A152905 * A078077 A078082 A307090

Adjacent sequences: A096598 A096599 A096600 * A096602 A096603 A096604

Keyword

nonn,tabf

Author

Gerald McGarvey, Aug 14 2004

Status

approved