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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A247943 2-dimensional array T(n, k) listed by antidiagonals giving the number of acyclic paths in the graph G(n, k) whose vertices are the integer lattice points (p, q) with 0 <= p < n and 0 <= q < k and with an edge between v and w iff the line segment [v, w] contains no other integer lattice points.

Table of values

n a(n)
1 0
2 2
3 2
4 6
5 60
6 6
7 12
8 1058
9 1058
10 12
11 20
12 25080
13 140240
14 25080
15 20
16 30
17 822594
18 58673472
19 58673472
20 822594
21 30
22 42
23 36195620
24 28938943114
25 490225231968
26 28938943114
27 36195620
28 42
29 56
30 2069486450

List of values

[0, 2, 2, 6, 60, 6, 12, 1058, 1058, 12, 20, 25080, 140240, 25080, 20, 30, 822594, 58673472, 58673472, 822594, 30, 42, 36195620, 28938943114, 490225231968, 28938943114, 36195620, 42, 56, 2069486450]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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