OFFSET
0,2
COMMENTS
The first n terms of this sequence coincide with the first n terms of the corresponding sequences for n X n sliding block puzzles (see Cross-references).
PROG
(Python) # uses alst(), swap() in A089473
nn = 13
start = "".join([chr(i) for i in range(45, 45+(nn+1)**2)]) # chr(45) is "-"
print(alst(start, (nn+1, nn+1), maxd=nn)) # Michael S. Branicky, Jan 02 2021
CROSSREFS
KEYWORD
more,nonn
AUTHOR
Hugo Pfoertner, Nov 27 2003
EXTENSIONS
a(10)-a(17) from Michael S. Branicky, Dec 28 2020
STATUS
approved