A321304 Triangle T(n,f): the number of bicolored connected cubic graphs on 2n vertices with f vertices of the first color.
1, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 5, 5, 5, 2, 2, 5, 10, 31, 46, 63, 46, 31, 10, 5, 19, 64, 248, 542, 931, 1052, 931, 542, 248, 64, 19, 85, 490, 2382, 7011, 15199, 23405, 27336, 23405, 15199, 7011, 2382, 490, 85, 509, 4595, 27233, 101002, 268675, 523246, 776657, 882321, 776657, 523246, 268675, 101002, 27233, 4595, 509
Offset: 0
Examples
The triangle starts: 0 vertices: 1; 2 vertices: 0, 0, 0; 4 vertices: 1, 1, 1, 1, 1; 6 vertices: 2, 2, 5, 5, 5, 2, 2; 8 vertices: 5, 10, 31, 46, 63, 46, 31, 10, 5; 10 vertices: 19, 64, 248, 542, 931, 1052, 931, 542, 248, 64, 19;
Links
- Andrew Howroyd, Table of n, a(n) for n = 0..440 (rows 0..20)
Crossrefs
Formula
T(n,f) = T(n,2n-f).
Extensions
Terms a(49) and beyond from Andrew Howroyd, Mar 11 2023
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