login
A358696
Number of self-avoiding closed paths in the 5 X n grid graph which pass through all vertices on four (left, right, upper, lower) sides of the graph.
2
1, 5, 36, 191, 1123, 6410, 37165, 214515, 1240200, 7165033, 41403125, 239227616, 1382302375, 7987125379, 46150853892, 266666446637, 1540838849619, 8903196975232, 51444004997119, 297251155267189, 1717561649837610, 9924328164015589, 57344252900906673, 331343672343272500, 1914553310297505893, 11062575457823993391, 63921216037276901284
OFFSET
2,2
LINKS
FORMULA
Conjecture: a(n) = 6 *a(n-1) + a(n-2) - 20 * a(n-3) + 37 * a(n-4) + 16 * a(n-5) - 12 * a(n-6) - 7 * a(n-7) + 5 * a(n-8) - a(n-9) for n > 10.
CROSSREFS
Row 5 of A333758.
Cf. A333515.
Sequence in context: A048535 A272150 A271254 * A227163 A271055 A212329
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Nov 27 2022
STATUS
approved