A358084
Sum of square end-to-end displacements over all n-step self-avoiding walks of A358036.
Original entry on oeis.org
0, 16, 88, 288, 1104, 3264, 12032, 34144, 115112, 323888, 1043360, 2903280, 9122592, 24993552, 77246888, 209811360, 637734248, 1726546928, 5170075216, 13965402144, 41331646184, 111361083152, 326576770784, 877687158464, 2554653282056, 6850500549888, 19812687702472, 53030550412576
Offset: 1
a(3) = 88 as, in the first quadrant, the three 3-step SAWs that have the first and last visited lattice point being mutually visible are:
.
X
|
X---. . X
| | |
X---. X---. X---.---.
.
The sum of square end-to-end displacements of these three walks is 1 + 5 + 5 = 11. They can be walked in eight different ways on a square lattice thus a(3) = 11 * 8 = 88.
A368614
Number of n-step self-avoiding walks on a 2D square lattice where each visited lattice point is either a neighbor of the first visited lattice point, else the first visited lattice point is directly visible (cf. A358036) from the lattice point when it is first visited.
Original entry on oeis.org
4, 8, 16, 24, 48, 80, 168, 296, 624, 1144, 2424, 4552, 9680, 18480, 39368, 76128, 162376, 317288, 677624, 1335688, 2856536, 5672576, 12149080, 24280768, 52079424, 104665200, 224825088, 454047672, 976721744, 1981083216, 4267578200, 8689274768, 18743542208, 38295782400, 82715689712
Offset: 1
a(4) = 24. For walks with a second step in the first quadrant, there are three 4-step saws where the first lattice point is either a neighbor or directly visible from each point as it is first visited. These are:
.
.---.---. .---. .
| | |
X---. . .
| |
X---. .
|
X---.
.
where 'X' marks the position of the first lattice point. These three walks can be taken in eight ways on the 2D square lattice, so the total number of walks is 3 * 8 = 24.
A358046
Number of n-step self-avoiding walks on a 2D square lattice where the first visited lattice point is directly visible from the last visited lattice point, and were only visited lattice points are considered when determining the visibility of points.
Original entry on oeis.org
4, 8, 32, 64, 240, 480, 1904, 3832, 13992, 29304, 103088, 219416, 765600, 1609176, 5611680, 11785240, 40641032, 86254960, 293015872, 628547128, 2108574592, 4556118936, 15143701888, 32875906992, 108521571624, 236390241280, 776007097296, 1695412485136, 5538287862344
Offset: 1
a(1) = 4 as after one step in any of the four available directions the lattice point stepped to and the starting point have no other points between them, so the first point is visible from the last for all four walks.
a(2) = 8 as there are 4*3 = 12 2-step SAWs, but the four walks which consist of two steps directly along the axes have a visited lattice point directly between the first and last points of the walk, so those two point are not visible from each other. Thus a(2) = 12 - 4 = 8.
a(3) = 32 as there are thirty-six 3-step SAWs, and of those, only the four walks directly along the axes have visited points between the first and last points, so a(3) = 36 - 4 = 32.
a(4) = 64 as there are one hundred 4-step SAWs which include four walks directly along the axes which have a first point that is not visible from the last. In the first quadrant there are four other walks which have points on the line between the first and last point, and these points have been visited by earlier steps. These walks are:
.
X .---X X
| | |
@---. @ @---. .---.
| | | | |
X---. X---. X---. X---@ X
.
where the first and last points are shown as 'X' and where the visited points on the line between these two points are shown as '@'. Each of the above walks can be walked in eight ways on the 2D square lattice, so the total number of walks where the first point is visible from the last is 100 - 4 - 4*8 = 100 - 36 = 64.
A359073
Sum of square end-to-end displacements over all n-step self-avoiding walks of A359709.
Original entry on oeis.org
0, 4, 16, 44, 160, 556, 1744, 12252, 15840, 98876, 138160, 709900, 1155616, 5098260, 11820656, 37085908, 111147104, 281078764, 932893104, 2255139900, 7295211968, 18928121236, 54864568720, 160016686500, 404167501888, 1331607134172, 2945597090384, 10805511468852, 21448743511648
Offset: 0
A359709
Number of n-step self-avoiding walks on a 2D square lattice whose end-to-end distance is an integer.
Original entry on oeis.org
1, 4, 4, 12, 28, 76, 164, 732, 1044, 4924, 6724, 30636, 43972, 190516, 313996, 1197908, 2284260, 7678188, 16257604, 50524252, 113052396, 341811828, 773714436, 2358452388, 5245994292, 16447462492, 35395532236, 115129727188, 238542983748, 804980005276
Offset: 0
a(3) = 12 as, in the first quadrant, there is one 3-step SAW whose end-to-end distance is an integer (1 unit):
.
X---.
|
X---.
.
This can be walked in 8 different ways on a 2D square lattice. There are also the four walks directly along the x and y axes, giving a total of 8 + 4 = 12 walks.
Showing 1-5 of 5 results.
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