A061173 One-fourth of fourth column of Lucas bisection triangle (odd part).

3, 70, 642, 4055, 20945, 95372, 398290, 1561683, 5836190, 21001410, 73300478, 249476600, 831342517, 2720979140, 8768966810, 27881856697, 87610794135, 272424413508, 839229287580, 2563768831145, 7773145679478

Offset: 0

Author

Wolfdieter Lang, Apr 20 2001

Keywords

• nonn
• easy

Comments

Numerator of g.f. is row polynomial sum(A061187(3,m)*x^m,m=0..5)/4.

Crossrefs

Cf. A005248, 2*A061171, A061172.

Formula

a(n)=A060924(n+3, 3)/4.

G.f.: (x+1)*(3-2*x)*(1+11*x-11*x^2+4*x^3)/(1-3*x+x^2)^4.