A215181 Number of nXnXn triangular 0..7 arrays with every horizontal row nondecreasing, first elements of rows nonincreasing, last elements of rows nondecreasing, and every row having the same average value

8, 20, 98, 892, 14826, 437416, 23336410, 2146457038, 337114516270, 86918737933870, 35883197315166396, 22870097395707859964, 22034812844398753721814, 31171558939019307119162084

Offset

1,1

Comments

Column 7 of A215182

Links

R. H. Hardin, Table of n, a(n) for n = 1..44

Example

Some solutions for n=4
.....4........6........3........6........3........4........3........3
....3.5......6.6......2.4......6.6......1.5......4.4......3.3......3.3
...3.4.5....6.6.6....2.2.5....6.6.6....0.4.5....2.3.7....2.3.4....0.4.5
..2.3.5.6..4.6.7.7..0.1.4.7..6.6.6.6..0.1.5.6..1.3.5.7..0.1.5.6..0.2.3.7

Crossrefs

Sequence in context: A365606 A007016 A129550 * A014584 A074472 A175429

Adjacent sequences: A215178 A215179 A215180 * A215182 A215183 A215184

Keyword

nonn

Author

R. H. Hardin Aug 05 2012

Status

approved