A307025 Number of (undirected) paths in the m X n knight graph (triangle read by rows with m = 1..n and n = 1..).

0, 0, 0, 0, 2, 56, 0, 4, 374, 14980, 0, 8, 2664, 302844, 19005336, 0, 12, 17556, 6530656, 1248702804, 278982789260, 0, 18, 121838, 151793054

Offset

1,5

Links

Table of n, a(n) for n=1..25.

Eric Weisstein's World of Mathematics, Graph Path

Eric Weisstein's World of Mathematics, Knight Graph

Formula

a(1, n) = 0.

a(2, n) = (1 - (-1)^n + 2*n*(n - 2))/4 for n > 1.

a(n, n) = A288033(n).

Example

0;
0, 0;
0, 2, 56;
0, 4, 374, 14980;
0, 8, 2664, 302844, 19005336;
0, 12, 17556, 6530656, 1248702804, 278982789260;
0, 18, 121838, 151793054, ...;

Crossrefs

Cf. A288033 (n X n knight graph).

Sequence in context: A210928 A210932 A278842 * A037176 A045819 A281198

Adjacent sequences: A307022 A307023 A307024 * A307026 A307027 A307028

Keyword

nonn,tabl,more

Author

Eric W. Weisstein, Mar 20 2019

Status

approved