OFFSET
1,1
FORMULA
EXAMPLE
T(1,2) = 17. Taking the first step right,left,forward or backward hits the box's edge after which the walks has three directions for the second step, giving 4*3 = 12 walks in all. A first step upward can be followed by a second step in five directions. The total number of 2-step walks is therefore 12+5 = 17.
.
The table begins:
.
5 17 52 148 400 1060 2700 6720 15760 36248 77856 163296 312760...
5 21 89 357 1424 5484 20960 78412 292168 1072272 3919000 14145220 50832492...
5 21 93 405 1789 7705 33048 139032 583256 2422480 10053452 41415564 170419680...
5 21 93 409 1849 8257 37097 164533 728808 3194636 13978148 60739156 263711448...
5 21 93 409 1853 8329 37877 171117 776065 3496769 15758504 70593984 315942684...
5 21 93 409 1853 8333 37961 172165 786089 3577129 16326745 74257917 337994448...
5 21 93 409 1853 8333 37965 172261 787445 3591637 16455441 75254865 344977177...
5 21 93 409 1853 8333 37965 172265 787553 3593341 16475617 75451269 346633713...
5 21 93 409 1853 8333 37965 172265 787557 3593461 16477709 75478437 346921841...
5 21 93 409 1853 8333 37965 172265 787557 3593465 16477841 75480957 346957465...
5 21 93 409 1853 8333 37965 172265 787557 3593465 16477845 75481101 346960453...
5 21 93 409 1853 8333 37965 172265 787557 3593465 16477845 75481105 346960609...
5 21 93 409 1853 8333 37965 172265 787557 3593465 16477845 75481105 346960613...
CROSSREFS
KEYWORD
AUTHOR
Scott R. Shannon, Aug 12 2020
STATUS
approved