A156172 Twice A002437.

2, 14, 610, 66734, 13631170, 4474847054, 2154541552930, 1430306187579374, 1252111529306645890, 1397549490970710103694, 1937106722774840873390050, 3264361741756845694953780014, 6572644038805857912224455865410, 15583184923914619905634967412688334, 42971525874172716914734880462487351970

Offset: 0

Author

N. J. A. Sloane, Nov 06 2009

Keywords

• nonn

Comments

Suggested by analogy with A000191.

Programs

Maple

Q:=proc(n) option remember; if n=0 then RETURN(1); else RETURN(expand((u^2+1)*diff(Q(n-1),u)+u*Q(n-1))); fi; end;
[seq(2*subs(u=sqrt(3),Q(2*n)),n=0..25)];