A366399 Triangle read by rows: T(n,k) is the number of paths traveling orthogonally on an n X k grid that visit every cell.
1, 1, 4, 1, 8, 20, 1, 14, 62, 276, 1, 22, 132, 1006, 4324, 1, 32, 336, 3610, 26996, 229348, 1, 44, 688, 12010, 109722, 1620034, 13535280, 1, 58, 1578, 38984, 602804, 12071462, 175905310, 3023313284, 1, 74, 3190, 122188, 2434670, 82550864, 1449655468, 43551685370, 745416341496
Offset: 1
Examples
T(n,k) is a triangular array read by rows: 1, 1, 4, 1, 8, 20, 1, 14, 62, 276, ... T(2,2) = 4: +---+---+ +---+---+ +---+---+ +---+---+ | | | | | | | | | | | | | **|** | | * | * | | **|** | | **|** | | | * | | * | * | | * | | | * | * | +---+---+ +---+---+ +---+---+ +---+---+ | | * | | * | * | | * | | | * | * | | **|** | | **|** | | **|** | | * | * | | | | | | | | | | | | | +---+---+ +---+---+ +---+---+ +---+---+
Extensions
More terms (using A332307) from Pontus von Brömssen, Oct 09 2023