38754732

Appears in sequences

• a(n) = 2^(n-1) + ((1 + (-1)^n)/4)*binomial(n, n/2).at n=26A027306
• a(n) = Sum_{i=0..n} binomial(2*n, i).at n=13A032443
• Expansion of ((1 + x - 2x^2) + (1+x)*sqrt(1-4x^2))/(2(1-4x^2)).at n=27A116406
• a(n) = Sum_{k=0..13} binomial(n, k).at n=26A219676