A333513
Square array T(n,k), n >= 2, k >= 2, read by antidiagonals, where T(n,k) is the number of self-avoiding closed paths on an n X k grid which pass through four corners ((0,0), (0,k-1), (n-1,k-1), (n-1,0)).
Original entry on oeis.org
1, 1, 1, 1, 1, 1, 1, 3, 3, 1, 1, 7, 11, 7, 1, 1, 17, 49, 49, 17, 1, 1, 41, 229, 373, 229, 41, 1, 1, 99, 1081, 3105, 3105, 1081, 99, 1, 1, 239, 5123, 26515, 44930, 26515, 5123, 239, 1, 1, 577, 24323, 227441, 674292, 674292, 227441, 24323, 577, 1
Offset: 2
Square array T(n,k) begins:
1, 1, 1, 1, 1, 1, ...
1, 1, 3, 7, 17, 41, ...
1, 3, 11, 49, 229, 1081, ...
1, 7, 49, 373, 3105, 26515, ...
1, 17, 229, 3105, 44930, 674292, ...
1, 41, 1081, 26515, 674292, 17720400, ...
-
# Using graphillion
from graphillion import GraphSet
import graphillion.tutorial as tl
def A333513(n, k):
universe = tl.grid(n - 1, k - 1)
GraphSet.set_universe(universe)
cycles = GraphSet.cycles()
for i in [1, k, k * (n - 1) + 1, k * n]:
cycles = cycles.including(i)
return cycles.len()
print([A333513(j + 2, i - j + 2) for i in range(11 - 1) for j in range(i + 1)])
A333246
Number of self-avoiding closed paths on an n X n grid which pass through NW corner.
Original entry on oeis.org
1, 7, 97, 4111, 532269, 212372937, 263708907211, 1013068026356375, 11955420069208095719, 432101605951906251627393, 47778407166747833830058004149, 16149888968763663448192636077980753, 16675786862526496319891707194153887550751, 52568166380872328447478940416604864445574575709
Offset: 2
a(2) = 1;
+--*
| |
*--*
a(3) = 7;
+--* +--*--* +--*--* +--*
| | | | | | | |
*--* *--*--* * * * *
| | | |
*--*--* *--*
+--*--* +--*--* +--*
| | | | | |
* *--* *--* * * *--*
| | | | | |
*--* *--* *--*--*
-
# Using graphillion
from graphillion import GraphSet
import graphillion.tutorial as tl
def A333246(n):
universe = tl.grid(n - 1, n - 1)
GraphSet.set_universe(universe)
cycles = GraphSet.cycles().including(1)
return cycles.len()
print([A333246(n) for n in range(2, 10)])
A333323
Number of self-avoiding closed paths on an n X n grid which pass through NW and SE corners.
Original entry on oeis.org
1, 3, 42, 1799, 232094, 92617031, 115156685746, 442641690778179, 5224287477491915786, 188825256606226776728029, 20879416139356164466643759334, 7057757437924198729598570424130207, 7287699030020917172151307665469211016474, 22973720258279267139936821063450448822110219653
Offset: 2
a(2) = 1;
+--*
| |
*--+
a(3) = 3;
+--*--* +--*--* +--*
| | | | | |
*--* * * * * *--*
| | | | | |
*--+ *--*--+ *--*--+
- Anthony J. Guttmann and Iwan Jensen, Table of n, a(n) for n = 2..27
- Anthony J. Guttmann and Iwan Jensen, Self-avoiding walks and polygons crossing a domain on the square and hexagonal lattices, arXiv:2208.06744 [math-ph], Aug 13 2022, Table D2 (with offset 1).
- Anthony J. Guttmann and Iwan Jensen, The gerrymander sequence, or A348456, arXiv:2211.14482 [math.CO], 2022.
-
# Using graphillion
from graphillion import GraphSet
import graphillion.tutorial as tl
def A333323(n):
universe = tl.grid(n - 1, n - 1)
GraphSet.set_universe(universe)
cycles = GraphSet.cycles().including(1).including(n * n)
return cycles.len()
print([A333323(n) for n in range(2, 10)])
A333247
Number of self-avoiding closed paths on an n X n grid which pass through NW and SW corners.
Original entry on oeis.org
1, 4, 47, 1843, 232905, 92729439, 115234959344, 442748883422394
Offset: 2
a(2) = 1;
+--*
| |
+--*
a(3) = 4;
+--*--* +--*--* +--* +--*
| | | | | | | |
* * * *--* * *--* * *
| | | | | | | |
+--*--* +--* +--*--* +--*
-
# Using graphillion
from graphillion import GraphSet
import graphillion.tutorial as tl
def A333247(n):
universe = tl.grid(n - 1, n - 1)
GraphSet.set_universe(universe)
cycles = GraphSet.cycles().including(1).including(n)
return cycles.len()
print([A333247(n) for n in range(2, 10)])
A333668
Triangle T(n,k), n >= 2, 0 <= k <= floor(n^2/2)-2*n+2, read by rows, where T(n,k) is the number of 2*(k+2*n-2)-cycles in the n X n grid graph which pass through four corners ((0,0), (0,n-1), (n-1,n-1), (n-1,0)).
Original entry on oeis.org
1, 1, 1, 4, 6, 1, 12, 58, 156, 146, 1, 24, 244, 1416, 5435, 12976, 16654, 7108, 1072, 1, 40, 696, 7076, 47965, 236628, 873610, 2348664, 4335724, 4958224, 3407276, 1298704, 205792
Offset: 2
T(4,1) = 4;
+--*--*--+ +--*--*--+ +--*--*--+ +--* *--+
| | | | | | | | | |
*--* * * *--* * * * *--* *
| | | | | | | |
*--* * * *--* * *--* * * *
| | | | | | | | | |
+--*--*--+ +--*--*--+ +--* *--+ +--*--*--+
Triangle starts:
=================================================================
n\k| 0 1 2 3 4 ... 8 ... 12 ... 18
---|-------------------------------------------------------------
2 | 1;
3 | 1;
4 | 1, 4, 6;
5 | 1, 12, 58, 156, 146;
6 | 1, 24, 244, 1416, 5435, ... , 1072;
7 | 1, 40, 696, 7076, 47965, ........... , 205792;
8 | 1, 60, 1590, 24960, 263770, ..................... , 4638576;
-
# Using graphillion
from graphillion import GraphSet
import graphillion.tutorial as tl
def A333668(n):
universe = tl.grid(n - 1, n - 1)
GraphSet.set_universe(universe)
cycles = GraphSet.cycles()
for i in [1, n, n * (n - 1) + 1, n * n]:
cycles = cycles.including(i)
return [cycles.len(2 * k).len() for k in range(2 * n - 2, n * n // 2 + 1)]
print([i for n in range(2, 8) for i in A333668(n)])
A333759
Number of self-avoiding closed paths in the n X n grid graph which pass through all vertices on four (left, right, upper, lower) sides of the graph.
Original entry on oeis.org
1, 1, 11, 191, 11346, 2002405, 1112939654, 1878223479450
Offset: 2
a(2) = 1;
+--+
| |
+--+
a(3) = 1;
+--+--+
| |
+ +
| |
+--+--+
a(4) = 11;
+--+--+--+ +--+--+--+ +--+--+--+
| | | | | |
+--*--* + +--* *--+ +--* +
| | | | | |
+--*--* + +--* *--+ +--* +
| | | | | |
+--+--+--+ +--+--+--+ +--+--+--+
+--+--+--+ +--+--+--+ +--+--+--+
| | | | | |
+ *--*--+ + *--* + + *--+
| | | | | | | |
+ *--*--+ + * * + + *--+
| | | | | | | |
+--+--+--+ +--+ +--+ +--+--+--+
+--+--+--+ +--+--+--+ +--+ +--+
| | | | | | | |
+ + + + + *--* +
| | | | | |
+ *--* + + + + *--* +
| | | | | | | | | |
+--+ +--+ +--+--+--+ +--+ +--+
+--+ +--+ +--+ +--+
| | | | | | | |
+ *--* + + * * +
| | | | | |
+ + + *--* +
| | | |
+--+--+--+ +--+--+--+
-
# Using graphillion
from graphillion import GraphSet
import graphillion.tutorial as tl
def A333759(n):
universe = tl.grid(n - 1, n - 1)
GraphSet.set_universe(universe)
cycles = GraphSet.cycles()
points = [i for i in range(1, n * n + 1) if i % n < 2 or ((i - 1) // n + 1) % n < 2]
for i in points:
cycles = cycles.including(i)
return cycles.len()
print([A333759(n) for n in range(2, 10)])
A333795
Number of self-avoiding closed paths on an n X n grid which pass through all points on the two diagonals of the grid.
Original entry on oeis.org
1, 0, 6, 68, 6102, 1404416, 1094802826, 2524252113468
Offset: 2
a(2) = 1;
+--+
| |
+--+
a(4) = 6;
+--*--*--+ +--*--*--+ +--*--*--+
| | | | | |
*--+--+ * *--+ +--* * +--+--*
| | | | | |
*--+--+ * *--+ +--* * +--+--*
| | | | | |
+--*--*--+ +--*--*--+ +--*--*--+
+--*--*--+ +--* *--+ +--* *--+
| | | | | | | | | |
* +--+ * * +--+ * * + + *
| | | | | | | | | |
* + + * * +--+ * * +--+ *
| | | | | | | | | |
+--* *--+ +--* *--+ +--*--*--+
-
# Using graphillion
from graphillion import GraphSet
import graphillion.tutorial as tl
def A333795(n):
universe = tl.grid(n - 1, n - 1)
GraphSet.set_universe(universe)
cycles = GraphSet.cycles()
points = [i + 1 for i in range(n * n) if i % n - i // n == 0 or i % n + i // n == n - 1]
for i in points:
cycles = cycles.including(i)
return cycles.len()
print([A333795(n) for n in range(2, 10)])
A333796
Number of self-avoiding closed paths on an n X n grid which pass through all points on the diagonal connecting NW and SE corners.
Original entry on oeis.org
1, 2, 22, 716, 73346, 23374544, 23037365786, 69630317879888
Offset: 2
a(2) = 1;
+--*
| |
*--+
a(3) = 2;
+--*--* +--*
| | | |
*--+ * * +--*
| | | |
*--+ *--*--+
a(4) = 22;
+--*--*--* +--*--*--* +--*--*--*
| | | | | |
*--+--* * *--+--* * *--+--* *
| | | | | |
*--*--+ * *--+ * + *
| | | | | |
*--*--*--+ *--*--+ *--+
+--*--*--* +--*--*--* +--*--*--*
| | | | | |
*--+ *--* *--+ *--* *--+ *
| | | | | |
*--* +--* * +--* *--+ *
| | | | | |
*--*--*--+ *--*--+ *--+
+--*--*--* +--*--*--* +--*--*--*
| | | | | |
* +--*--* * +--* * * +--* *
| | | | | | | | | |
* *--+--* *--* + * * * + *
| | | | | | | |
*--*--*--+ *--+ *--* *--+
+--*--* +--*--* +--*--*
| | | | | |
*--+ *--* *--+ * *--+ *
| | | | | |
*--+ * *--* +--* * +--*
| | | | | |
*--+ *--*--*--+ *--*--+
+--*--* +--* *--* +--* *--*
| | | | | | | | | |
* +--* * +--* * * +--* *
| | | | | |
* *--+--* *--*--+ * * *--+ *
| | | | | | | |
*--*--*--+ *--+ *--* *--+
+--* *--* +--* +--*
| | | | | | | |
* + * * * +--*--* * +--*--*
| | | | | | | |
* *--+ * *--*--+ * * *--+ *
| | | | | | | |
*--*--*--+ *--+ *--* *--+
+--* +--* +--*
| | | | | |
* +--* * +--* * + *--*
| | | | | | | |
*--* +--* * +--* * *--+ *
| | | | | |
*--*--+ *--*--*--+ *--*--*--+
+--*
| |
* +
| |
* *--+--*
| |
*--*--*--+
-
# Using graphillion
from graphillion import GraphSet
import graphillion.tutorial as tl
def A333796(n):
universe = tl.grid(n - 1, n - 1)
GraphSet.set_universe(universe)
cycles = GraphSet.cycles()
points = [i + 1 for i in range(n * n) if i % n - i // n == 0]
for i in points:
cycles = cycles.including(i)
return cycles.len()
print([A333796(n) for n in range(2, 10)])
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