OFFSET
2,2
LINKS
Rigoberto Flórez, Leandro Junes, and José L. Ramírez, Further Results on Paths in an n-Dimensional Cubic Lattice, Journal of Integer Sequences, Vol. 21 (2018), Article 18.1.2.
R. K. Guy, Catwalks, sandsteps and Pascal pyramids, J. Integer Sequences, Vol. 3 (2000), Article #00.1.6.
MAPLE
b:= proc(n, k) option remember; `if`(min(n, k)<0, 0,
`if`(max(n, k)=0, 1, b(n-1, k-1)+4*b(n-1, k)+b(n-1, k+1)))
end:
a:= n-> b(n, 2):
seq(a(n), n=2..25); # Alois P. Heinz, Oct 28 2021
CROSSREFS
KEYWORD
nonn,walk
AUTHOR
N. J. A. Sloane, Jan 26 2000
EXTENSIONS
More terms and title improved by Sean A. Irvine, Oct 28 2021
STATUS
approved