A323141 - OEIS

A323141

Number of self-trapped uncrossed king's paths on an infinite board after n steps, reduced for symmetry.

0, 0, 0, 0, 2, 19, 150, 1043, 6843, 43192, 266529, 1619983, 9746883, 58220994, 345919915

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,5

LINKS

EXAMPLE

a(5) = 2: There are 2 walks where the king is blocked after 5 steps, because for the diagonal moves it would have to cross its previous path.

o 2 o o 3 o

/ \ / \

3 5 1 4 - - - 5 2

| / / /

4 S o S - - - 1 o

CROSSREFS

KEYWORD

nonn,more,hard

AUTHOR

STATUS

approved