A067307 One-fourth of fourth column of triangle A067304.

7, 71, 768, 8920, 109232, 1390800, 18237952, 244701440, 3343713024, 46374830848, 651170275328, 9238908291072, 132251092529152, 1907671386263552, 27701755840561152, 404632598092447744

Offset

0,1

Links

Table of n, a(n) for n=0..15.

Formula

a(n)= A067304(n+3, 3)/4 = (A067297(n+3)-(b(n+3)+b(n+2)+4*b(n+1)))/4, n>=0, with b(n) := A064340(n).

G.f.: 4(3+10*c(4*x)+12*c(4*x)^2+3*c(4*x)^3)*(c(4*x)^3)/(1+c(4*x))^4, with c(x) g.f. of A000108 (Catalan).

Crossrefs

Sequence in context: A065537 A048552 A260033 * A334135 A357155 A268702

Adjacent sequences: A067304 A067305 A067306 * A067308 A067309 A067310

Keyword

nonn,easy

Author

Wolfdieter Lang, Feb 05 2002

Status

approved