1512900

Appears in sequences

• Squares n with digit 1 that remain positive square after omitting all 1's from n.at n=23A176899
• Numbers with prime factorization p^2*q^2*r^2*s^2 where p, q, r, and s are distinct primes.at n=21A190377
• Number of (n+2) X (1+2) 0..1 arrays with no 3 x 3 subblock diagonal sum one and no antidiagonal sum one.at n=7A255075
• T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with no 3x3 subblock diagonal sum one and no antidiagonal sum one.at n=28A255082
• a(n) is the least perfect square average of two consecutive primes with 2*n gap between them, or -1 if no such number exists.at n=22A360751