A046170 Number of self-avoiding walks on a 2-D lattice of length n which start at the origin, take first step in the {+1,0} direction and whose vertices are always nonnegative in x and y.

1, 2, 5, 12, 30, 73, 183, 456, 1151, 2900, 7361, 18684, 47652, 121584, 311259, 797311, 2047384, 5260692, 13542718, 34884239, 89991344, 232282110, 600281932, 1552096361, 4017128206, 10401997092, 26957667445, 69892976538, 181340757857, 470680630478, 1222433229262, 3175981845982

Offset

1,2

Links

Siqi Wang, Table of n, a(n) for n = 1..40

Stephen A. Silver, C program

Siqi Wang, C++ program used to generate the sequence.

Eric Weisstein's World of Mathematics, Self-Avoiding Walk

Formula

a(n) = A038373(n)/2. - Siqi Wang, Jul 15 2022

Crossrefs

Cf. A038373, A046171.

Sequence in context: A101911 A052109 A157748 * A369145 A262320 A062423

Adjacent sequences: A046167 A046168 A046169 * A046171 A046172 A046173

Keyword

nonn,walk

Author

Eric W. Weisstein

Extensions

More terms from Stephen A. Silver

More terms from Siqi Wang, Jul 15 2022

Status

approved