OFFSET
0,4
LINKS
Alois P. Heinz, Rows n = 0..50, flattened
Alois P. Heinz, Animation of T(5,12)=91 walks
Wikipedia, Lattice_path
Wikipedia, Self-avoiding walk
FORMULA
Sum_{k=n..n*(n+3)/2} (k+1) * T(n,k) = A284231(n).
EXAMPLE
Triangle T(n,k) begins:
1;
. 1, 1;
. . 2, 1, 1, 1;
. . . 4, 4, 4, 7, 3, 1, 1;
. . . . 9, 8, 16, 21, 17, 15, 10, 9, 4, 1, 1;
. . . . . 21, 22, 54, 87, 87, 116, 99, 91, 78, 42, 31, 17, 10, 5, 1, 1;
CROSSREFS
KEYWORD
nonn,tabf,walk
AUTHOR
Alois P. Heinz, Mar 26 2017
STATUS
approved