OFFSET
1,4
COMMENTS
For n > 1, n < 5, this shares the sequence with n-1 in A140517. Cycles are not reduced by symmetry (rotation, translation or mirroring). The grid can only have one cycle.
LINKS
Cracking The Cryptic, The Trouble With Circular Reasoning Is.... (!), YouTube.
Jimmy MÃ¥rdell, Python code used for generation of the sequence.
EXAMPLE
For n = 4, there are 13 valid cycles:
.
1 2 3 4
###. .### .... ....
#.#. .#.# .### ###.
###. .### .#.# #.#.
.... .... .### ###.
.
5 6 7 8
#### .... ###. .###
#..# #### #.#. .#.#
#### #..# #.#. .#.#
.... #### ###. .###
.
9 10 11 12
.### ###. #### ####
##.# #.## #..# #..#
#..# #..# #.## ##.#
#### #### ###. .###
.
13
####
#..#
#..#
####
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Niklas Gustavsson, Jan 02 2024
STATUS
approved