A039648 Number of n-step self-avoiding paths on the first octant of a 3-dimensional cubic lattice, starting at the origin.
1, 3, 9, 33, 123, 489, 1947, 7977, 32817, 137253, 576993, 2452071, 10468245, 45032733, 194475321, 844608567, 3680153043, 16105438515, 70677344403, 311242931097, 1373860647453, 6081635195553
Offset: 0
Extensions
a(19)-a(21) from Scott R. Shannon, Aug 14 2020
Title clarified by Sean A. Irvine, Feb 20 2021