A348057 Number of n-step self-avoiding walks on three quadrants of a 2D square lattice.

1, 4, 10, 28, 74, 202, 534, 1442, 3822, 10258, 27202, 72718, 192840, 514228, 1363342, 3629316, 9619264, 25575326, 67765590, 180001304, 476807826, 1265567600, 3351529410, 8890447682, 23538665948, 62409037914, 165202281046

Offset: 0

Author

Scott R. Shannon, Sep 26 2021

Keywords

• nonn
• walk

Examples

			a(2) = 10. Assuming the lower left quadrant is the one removed then a walk of left-down or down-left is not permitted, so the total number of 2-step walks is 4 * 3 - 2 = 10.
		

Crossrefs

Cf. A001411 (four quadrants), A116903 (two quadrants), A038373 (one quadrant), A129700 (half quadrant).