A363090 Number of 3-dimensional directed animals of size n.

1, 3, 12, 52, 237, 1113, 5339, 26011, 128247, 638346, 3201967, 16164384, 82044151, 418352107, 2141761669, 11003117220

Offset: 1

Author

Joerg Arndt and Márk Péter Légrádi, May 19 2023

Keywords

• nonn
• hard
• more

Comments

Fixed 3-dimensional fixed polycubes with neighborhood vectors [1, 0, 0], [0, 1, 0], and [0, 0, 1].

A005773 is the 2-dimensional equivalent: fixed polyominoes with neighborhood vectors [1, 0] and [0, 1].

Using neighborhood vectors [+-1, 0, 0], [0, +-1, 0], and [0, 0, +-1] gives A001931.

Crossrefs

Cf. A005773.

Extensions

a(14)-a(16) from Johann Peters, Nov 21 2024