OFFSET
1,2
COMMENTS
a(1)-a(8) verified and a(9)-a(10) computed by John Mason.
LINKS
Ishino Keiichiro, Polyedge, Puzzle will be played, 2009.
EXAMPLE
There are a(3) = 7 free 3-polysticks in 3 dimensions: A019988(3) = 5 properly 1- or 2-dimensional (straight, "U", "T", "L", and skew, similar to the 5 tetrominoes) and 2 properly 3-dimensional (one path-like and one with a vertex of degree 3).
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Pontus von Brömssen, Sep 09 2023
EXTENSIONS
a(11) derived from Ishino Keiichiro's website (sum of 2-sided 2D-edges and 3D-edges), added by Pontus von Brömssen, Dec 21 2023
STATUS
approved