|
|
A359988
|
|
Number of edge cuts in the 3 X n grid graph.
|
|
2
|
|
|
3, 105, 3665, 123215, 4051679, 131630449, 4248037953, 136587740399, 4382607093471, 140457446235441, 4498520188148993, 144023056568886959, 4610014925578108703, 147543642097619999089, 4721816707356538941633, 151105755554498621737583, 4835522406931884652356447
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
FORMULA
|
a(n) = 54*a(n-1) - 777*a(n-2) + 2390*a(n-3) - 1736*a(n-4) + 256*a(n-5) for n > 5.
G.f.: x*(3 - 57*x + 326*x^2 - 280*x^3 + 32*x^4)/((1 - 32*x)*(1 - 22*x + 73*x^2 - 54*x^3 + 8*x^4)).
|
|
PROG
|
(PARI) Vec((3 - 57*x + 326*x^2 - 280*x^3 + 32*x^4)/((1 - 32*x)*(1 - 22*x + 73*x^2 - 54*x^3 + 8*x^4)) + O(x^20))
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|