A214121 Irregular array T(n,k) of the numbers of non-extendable (complete) non-self-adjacent simple paths ending at each of a minimal subset of nodes within a square lattice bounded by rectangles with nodal dimensions n and 3, n >= 2.
5, 0, 14, 2, 2, 0, 33, 4, 6, 0, 75, 6, 13, 0, 16, 0, 165, 8, 27, 0, 32, 0, 353, 10, 57, 0, 62, 0, 60, 0, 747, 12, 119, 0, 124, 0, 109, 0, 1577, 14, 247, 0, 250, 0, 206, 0, 184, 0, 3327, 16, 515, 0, 508, 0, 399, 0, 323, 0, 7015, 18, 1079, 0, 1046, 0, 790, 0, 590
Offset: 2
Examples
When n = 2, the number of times (NT) each node in the rectangle is the end node (EN) of a complete non-self-adjacent simple path is EN 0 1 2 3 4 5 NT 5 0 5 5 0 5 To limit duplication, only the top left-hand corner 5 and the 0 to its right are stored in the sequence, i.e. T(2,1) = 5 and T(2,2) = 0.
Links
- C. H. Gribble, Computed characteristics of complete non-self-adjacent paths in a square lattice bounded by various sizes of rectangle.
- C. H. Gribble, Computes characteristics of complete non-self-adjacent paths in square and cubic lattices bounded by various sizes of rectangle and rectangular cuboid respectively.
Formula
Let T(n,k) denote an element of the irregular array then it appears that
T(n,k) = 0, n >= 3, k = 2j, j >= 2,
T(n,1) - 2T(n-1,1) - T(n-4,1) - 8 = 0, n >= 8,
T(n,2) = 2(n-2), n >= 2,
T(n,3) - 2T(n-1,3) - T(n-4,3) + 2(n-7) = 0, n >= 9,
T(n,5) - 2T(n-1,5) - T(n-4,5) + 8(n-7) = 0, n >= 10,
T(n,7) - 2T(n-1,7) - T(n-4,7) + 20(n-8) + 8 = 0, n >= 11,
T(n,9) - 2T(n-1,9) - T(n-4,9) + 46(n-9) + 30 = 0, n >= 13,
T(n,11) - 2T(n-1,11) - T(n-4,11) + 104(n-10) + 84 = 0, n >= 15,
T(n,13) - 2T(n-1,13) - T(n-4,13) + 226(n-11) + 202 = 0, n >= 15.
Extensions
Comment corrected by Christopher Hunt Gribble, Jul 22 2012
Comments