1664100

Appears in sequences

• Numbers with prime factorization p^2*q^2*r^2*s^2 where p, q, r, and s are distinct primes.at n=23A190377
• Number of 4Xn 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 0 1 1 vertically.at n=12A207369
• Number of 4 X n arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, with every occupancy equal to zero or two.at n=9A221382