OFFSET
1,4
COMMENTS
Numbers a(n) are a by-product of the exhaustive computation done for A336660. They were communicated privately by Hugo Pfoertner and Hermann Jurksch.
For historical background see link section "Pictures of all different solutions for n <= 11".
LINKS
Rainer Rosenthal, Illustration of a(4).
Rainer Rosenthal, Illustration of a(8).
Rainer Rosenthal, Data of all different solutions for n <= 11, October 2020.
Rainer Rosenthal, Pictures of all different solutions for n <= 11, October 2020.
EXAMPLE
The square with side length s has lower left corner (x_s,y_s).
The a(8) = 8 solutions come in 6 main variations:
x8 y8 x7 y7 x6 y6 x5 y5 x4 y4 x3 y3 x2 y2 x1 y1
V1 0 0 0 2 4 6 5 5 2 7 6 4 1 7 4 10
V2 0 0 2 3 7 0 5 2 7 5 6 1 8 8 10 7
V3+ 0 0 3 7 0 3 2 6 5 5 1 7 7 4 3 6
+ .. .. .. .. .. .. .. .. .. .. .. .. .. .. 8 8
V4+ 0 0 3 7 0 3 2 6 5 6 1 7 6 9 4 10
+ .. .. .. .. .. .. .. .. .. .. .. .. .. .. 8 8
V5 0 0 4 6 1 3 5 5 2 7 6 4 3 10 2 9
V6 0 0 4 6 5 5 2 4 6 3 3 7 7 2 9 4
The two solutions in V3 are "1-siblings", i.e., they are equal except for (x1,y1).
Likewise V4 consists of two 1-siblings. See illustration of a(8) in the link section.
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Rainer Rosenthal, Sep 19 2020
EXTENSIONS
a(4) and a(8) corrected by Rainer Rosenthal, Oct 02 2020
STATUS
approved