23865

Appears in sequences

• a(n) = a(n-1) + a(n-2) + 1, with a(0) = 1 and a(1) = 7.at n=18A022321
• McKay-Thompson series of class 38A for Monster.at n=50A058657
• Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1010-1111-1000 pattern in any orientation.at n=16A146646
• a(n) = (prime(n))^2 - (nonprime(n))^2.at n=37A161757