A391808 Number of topological sequences of three dimensional lattice points with depth n and the largest possible index.

1, 0, 2, 1, 3, 9, 3, 10, 5, 1, 3, 9

Offset

0,3

Comments

See A387672 for the definition of a topological sequence.

Links

Table of n, a(n) for n=0..11.

Example

a(2) = 2: {(0, 0, 0), (0, 1, 0)}, {(0, 0, 0), (1, 0, 0)}.
a(3) = 1: {(0, 0, 0), (1, 0, 0), (0, 1, 0)}.
a(4) = 3: {(0, 0, 0), (0, 0, 1), (1, 0, 0), (0, 1, 0)}, {(0, 0, 0), (0, 1, 0), (1, 0, 0), (0, 2, 0)}, {(0, 0, 0), (1, 0, 0), (2, 0, 0), (0, 1, 0)}.

Crossrefs

Cf. A000219, A000293, A002836, A207542, A387672.

Sequence in context: A076240 A099644 A369446 * A058113 A374447 A249456

Adjacent sequences: A391805 A391806 A391807 * A391809 A391810 A391811

Keyword

nonn,more

Author

John Tyler Rascoe, Dec 20 2025

Status

approved