OFFSET
1,1
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 1..21
V. Kotesovec, Non-attacking chess pieces, 6ed, 2013, p. 69-71.
FORMULA
Limit n->infinity (a(n))^(1/n^2) = 1.503048082... (see A085850)
EXAMPLE
Neighbors for n=4 (dots represent spaces):
. o..o..o..o
. |\ |\ |\ |
. | \| \| \|
. o..o..o..o
. |\ |\ |\ |
. | \| \| \|
. o..o..o..o
. |\ |\ |\ |
. | \| \| \|
. o..o..o..o
CROSSREFS
Cf. circle A000204, line A000045, arrays: ne-sw nw-se A067965, e-w ne-sw nw-se A067963, e-w n-s nw-se A066864, e-w ne-sw n-s nw-se A063443, n-s A067966, e-w n-s A006506, nw-se A067962, toruses: bare A002416, ne-sw nw-se A067960, ne-sw n-s nw-se A067959, e-w ne-sw n-s nw-se A067958, n-s A067961, e-w n-s A027683, e-w ne-sw n-s A066866.
KEYWORD
nonn,nice,hard
AUTHOR
R. H. Hardin, Feb 02 2002
EXTENSIONS
Terms a(14)-a(18) from Vaclav Kotesovec, May 01 2012
STATUS
approved