OFFSET
0,3
COMMENTS
Lattice points may have negative coordinates, and different walks may differ in length. All walks are self-avoiding.
All terms are odd.
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..175
MAPLE
s:= proc(n) option remember;
`if`(n=0, [[]], map(x-> seq([x[], i], i=[-1, 1]), s(n-1)))
end:
b:= proc(l) option remember; (n-> `if`(l=[0$n], 1, add((h-> `if`(
add(i^2, i=h)<add(i^2, i=l), b(sort(h)), 0))(l+x), x=s(n))))(nops(l))
end:
a:= n-> b([n$4]):
seq(a(n), n=0..16);
CROSSREFS
KEYWORD
nonn,walk
AUTHOR
Alois P. Heinz, Oct 07 2022
STATUS
approved