A175900 Number of lattice paths from (0,0) to (n,n) using steps S={(k,0),(0,k),(1,1)|0<k<=4} which never go above the line y=x.

1, 2, 9, 57, 411, 3150, 25274, 209719, 1784909, 15495058, 136672624, 1221370092, 11034687854, 100623850938, 924917387599, 8560734224711, 79717622732369, 746322905220237, 7020573752016609, 66324819580927731, 629004053328092981

Offset

0,2

Links

Table of n, a(n) for n=0..20.

Crossrefs

Cf. A006318, A175895, A175896

Sequence in context: A295775 A223381 A175896 * A175912 A218824 A111545

Adjacent sequences: A175897 A175898 A175899 * A175901 A175902 A175903

Keyword

nonn

Author

Eric Werley, Dec 05 2010

Status

approved