A300694 a(n) = number of edges in a cocoon concertina n-cube.

0, 1, 13, 139, 1605, 20741

Offset

0,3

Comments

n-place formulas in first-order logic like Ax Ey P(x, y) or Ex P(x, x) can be ordered by implication. This Hasse diagram has A300696(n) vertices and a(n) edges.

The corresponding sequence for convex concertina n-cubes is A300693.

Links

Table of n, a(n) for n=0..5.

Tilman Piesk, Formulas in predicate logic (Wikiversity)

Tilman Piesk, Image of a cocoon concertina square with 13 edges

Tilman Piesk, Lists of edges for n=2..5

Tilman Piesk, Python code used to generate the sequence

Example

The cocoon concertina square has the A300693(2) = 6 outer and 7 inner edges, giving a(n) = 13 in total.

Crossrefs

Cf. A300696, A300693.

Sequence in context: A125425 A016145 A351812 * A193708 A195464 A365999

Adjacent sequences: A300691 A300692 A300693 * A300695 A300696 A300697

Keyword

nonn,more

Author

Tilman Piesk, Mar 24 2018

Status

approved