A167402 Number of n-step walks on square lattice, self-avoiding until the last step.

0, 0, 4, 12, 44, 116, 356, 948, 2772, 7396, 20972, 56108, 156236, 418228, 1151556, 3081180, 8421052, 22514652, 61207972, 163518308, 442769316, 1181982628, 3190663628, 8511628124, 22920057932, 61104234356, 164212633412

Offset: 0

Author

Vadim Sheikhman (vvsshh(AT)gmail.com), Nov 02 2009

Keywords

• nonn

Comments

A001411(n)=4^n-(a(n)+4*(a(n-1)+4*(a(n-2)+...)))

Crossrefs

See references given for A001411.

Formula

a(n) = 4*A001411(n-1)-A001411(n), n>0. [From Vladeta Jovovic, Nov 02 2009]

Extensions

More terms from Vladeta Jovovic, Nov 02 2009