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A341922
Number of simple 3-connected triangulations of a disk with n nodes.
2
1, 1, 4, 15, 64, 293, 1414, 7102, 36809, 195676, 1062176, 5867676, 32901124, 186866589, 1073261418, 6225028476, 36420849235, 214744648169, 1275005642668, 7617704400227, 45772485843616, 276460659973100, 1677717692649544, 10225697003966360, 62575895785795084
OFFSET
4,3
COMMENTS
A triangulation is simple if it contains no separating 3-cycle.
LINKS
EXAMPLE
The a(5) = 1 triangulation is:
o-------o
| \ / |
| o |
| / \ |
o-------o
PROG
(PARI) \\ R(n, m) defined in A210664.
seq(n)={my(v=R(n, 0)); for(m=1, n-1, v+=concat(vector(m), R(n-m, m))); v}
CROSSREFS
Antidiagonal sums of A210664.
Sequence in context: A353264 A117669 A323789 * A007526 A233536 A349202
KEYWORD
nonn
AUTHOR
Andrew Howroyd, Feb 24 2021
STATUS
approved