A188148 Number of 3-step self-avoiding walks on an n X n square summed over all starting positions.
0, 8, 44, 104, 188, 296, 428, 584, 764, 968, 1196, 1448, 1724, 2024, 2348, 2696, 3068, 3464, 3884, 4328, 4796, 5288, 5804, 6344, 6908, 7496, 8108, 8744, 9404, 10088, 10796, 11528, 12284, 13064, 13868, 14696, 15548, 16424, 17324, 18248, 19196, 20168, 21164
Offset: 1
Keywords
Examples
Some solutions for 3 X 3: ..0..3..0....0..0..0....0..1..0....1..0..0....0..1..0....0..0..0....0..3..0 ..0..2..0....0..3..0....0..2..3....2..0..0....0..2..0....3..2..1....0..2..1 ..0..1..0....0..2..1....0..0..0....3..0..0....0..3..0....0..0..0....0..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..50
Crossrefs
Cf. A188147.
Formula
Empirical: a(n) = 12*n^2 - 24*n + 8 for n>1.
Conjectures from Colin Barker, Apr 26 2018: (Start)
G.f.: 4*x^2*(2 + 5*x - x^2) / (1 - x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>4.
(End)
Comments