A271465 Array read by antidiagonals: T(n,m) = number of self-avoiding walks of any length from NW to SW corners on a grid with n rows and m columns.
1, 1, 1, 1, 2, 1, 1, 3, 4, 1, 1, 4, 11, 8, 1, 1, 5, 28, 38, 16, 1, 1, 6, 69, 178, 126, 32, 1, 1, 7, 168, 844, 1008, 415, 64, 1, 1, 8, 407, 4012, 8590, 5493, 1369, 128, 1, 1, 9, 984, 19072, 74148, 81445, 29879, 4521, 256, 1
Offset: 1
Examples
The start of the sequence as table: * 1 1 1 1 1 1 1 ... * 1 2 3 4 5 6 7 ... * 1 4 11 28 69 168 407 ... * 1 8 38 178 844 4012 19072 ... * 1 16 126 1008 8590 74148 638472 ... * 1 32 415 5493 81445 1246850 19011465 ... * 1 64 1369 29879 761047 20477490 550254085 ... * ...
Links
- Andrew Howroyd, Table of n, a(n) for n = 1..378
Crossrefs
Formula
T(1,n)=1, T(2,n)=n, T(n,1)=1, T(n,2)=2^(n-1).