OFFSET
1,2
COMMENTS
There is an edge between v = (p, q) and w = (r, s) iff p - r and q - s are coprime.
G(3, 3) is used for Android screen lock security patterns (see StackExchange link).
The nonzero entries on the diagonal of this sequence comprise the row sums of A247944.
LINKS
StackExchange, Combination of smartphones' pattern password, 2014
EXAMPLE
G(2,2) is the complete graph on 4 vertices, hence T(2, 2) = 4*3 + 4*3*2 + 4*3*2*1 = 60.
T(n, k) for n + k <= 8 is as follows:
.0........2...........6...........12..........20.......30..42
.2.......60........1058........25080......822594.36195620
.6.....1058......140240.....58673472.28938943114
12....25080....58673472.490225231968
20...822594.28938943114
30.36195620
42
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Rob Arthan, Sep 27 2014
STATUS
approved