530876

Appears in sequences

• Number of regions after n generations of symmetrized Conant Gasket.at n=21A335703
• a(n) = A335703(2n+1).at n=10A337268
• Expansion of g/(2 - g^2)^2, where g = 1+x*g^3 is the g.f. of A001764.at n=7A391463