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%I #4 Feb 05 2015 14:10:45
%S 1,3,14,71,370,1950,10332,54895,292106,1555706,8289732,44186710,
%T 235575028,1256093084,6698073528,35719158591,190488112122,
%U 1015885525794,5417869631028,28894620083346,154102115782812
%N Expansion of (1-x^2*c(x)^4)/(1-3*x*c(x)^2), c(x) the g.f. of A000108.
%C Apply the inverse of the Riordan array (1/(1-x^2),x/(1+x)^2) to 3^n. Hankel transform is A001653.
%F Conjecture: +3*(n+1)*a(n) +2*(-26*n+7)*a(n-1) +16*(18*n-25)*a(n-2) +256*(-2*n+5)*a(n-3)=0. - _R. J. Mathar_, Feb 05 2015
%F Conjecture: 3*(2*n+3)*(n+1)*a(n) +2*(-28*n^2-52*n+21)*a(n-1) +32*(2*n+5)*(2*n-3)*a(n-2)=0. - _R. J. Mathar_, Feb 05 2015
%Y Cf. A090317.
%K easy,nonn
%O 0,2
%A _Paul Barry_, Mar 13 2009