22358088723domain: NAppears in sequencesa(n) = cosh( (2n - 1)*arcsinh(sqrt(2)) )^2 = 1 - cos( (2n - 1)*arcsin(sqrt(3)) )^2.at n=5A146313a(n) = 10*a(n-1)-a(n-2)-4 with a(1)=1 and a(2)=3.at n=11A171640Expansion of x*(1 + 2*x - 96*x^2 - 148*x^3 + 45*x^4 + 50*x^5 + 2*x^6)/(1 - 99*x^2 + 99*x^4 - x^6).at n=13A268251