1017920

Appears in sequences

• Number of binary strings of length n with equal numbers of 0010 and 0100 substrings.at n=21A164166
• G.f.: Sum_{n>=0} A155585(n)^2 * log(1/(1-2*x))^n/n!, where 1/(1-2*x+2*x^2) = Sum_{n>=0} A155585(n)*log(1/(1-2*x))^n/n!.at n=10A167532
• Free polyominoes with 4n squares, having 90-degree rotational symmetry about a square corner.at n=12A234009