A067306 - OEIS

A067306

One-fourth of third column of triangle A067304.

1, 8, 75, 796, 9176, 111936, 1421968, 18618560, 249542400, 3407171584, 47226230528, 662805371904, 9400304896000, 134517761982464, 1939837469085696, 28162286932246528, 411276783645753344

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OFFSET

0,2

LINKS

Table of n, a(n) for n=0..16.

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: A231617 A094735 A383951 * A361528 A261065 A071720

Adjacent sequences: A067303 A067304 A067305 * A067307 A067308 A067309

KEYWORD

nonn,easy

AUTHOR

Wolfdieter Lang, Feb 05 2002

STATUS

approved