104919

Appears in sequences

• Expansion of 1/(1-x*sqrt(4*x^2+1)-2*x^2).at n=15A249512
• a(n) = 2*(a(n-1)+a(n-2)+a(n-3))-a(n-4) for n >= 4, with initial terms -1, 2, 3, 6.at n=12A317973