206657

Appears in sequences

• Floor((x^n - (1-x)^n)/sqrt(3)+.5) where x = (sqrt(3)+1)/2.at n=40A136422
• Number of fixed-point free involutions in the n-fold iterated wreath product of C_2.at n=5A332758
• Number of fixed-point free involutions in a fixed Sylow 2-subgroup of the symmetric group of degree 2n.at n=16A332840
• Number of fixed-point free involutions in a fixed Sylow 2-subgroup of the symmetric group of degree 2n.at n=17A332840
• Number of fixed-point free involutions in a fixed Sylow 2-subgroup of the symmetric group of degree 4n.at n=8A332869