a(n) = ((1 + sqrt(4*n^2 + 1))^n - (1 - sqrt(4*n^2 + 1))^n)/(2^n * sqrt(4*n^2 + 1)).

A320565

a(n) = ((1 + sqrt(4*n^2 + 1))^n - (1 - sqrt(4*n^2 + 1))^n)/(2^n * sqrt(4*n^2 + 1)).

Terms

    a(0) =0a(1) =1a(2) =1a(3) =10a(4) =33a(5) =701a(6) =4033a(7) =132301a(8) =1089921a(9) =48460114a(10) =520210801a(11) =29215223489a(12) =386721507745

External references