login
A067306
One-fourth of third column of triangle A067304.
0
1, 8, 75, 796, 9176, 111936, 1421968, 18618560, 249542400, 3407171584, 47226230528, 662805371904, 9400304896000, 134517761982464, 1939837469085696, 28162286932246528, 411276783645753344
OFFSET
0,2
FORMULA
a(n)= A067304(n+2, 2)/4 = (A067297(n+2) - (A064340(n+2)+A064340(n+1)))/4, n>=0.
G.f.: (3+10c(4*x)+3*c(4*x)^2)*(c(4*x)^3)/(1+c(4*x))^4, with c(x) g.f. of A000108 (Catalan).
CROSSREFS
Sequence in context: A268085 A231617 A094735 * A361528 A261065 A071720
KEYWORD
nonn,easy
AUTHOR
Wolfdieter Lang, Feb 05 2002
STATUS
approved