21312500

Appears in sequences

• Row sums of convolution triangle A030523.at n=13A039717
• Expansion of (1+x)*(1+2*x)*(1-x)/(1-5*x^2+5*x^4).at n=26A217777
• a(n) = Sum_{k>=0} (-1)^k*binomial(n,5*k+3).at n=28A289388