216545

Appears in sequences

• Nonprime numbers n such that phi(n) divides n^2 - 1, where phi(n) (A000010) is Euler's totient function.at n=31A098271
• Octagonal numbers (A000567) in which parity of digits alternates.at n=27A297647
• Terms of A324315 (squarefree integers m > 1 such that if prime p divides m, then the sum of the base p digits of m is at least p) that are also octagonal numbers (A000567) with index equal to their largest prime factor.at n=13A324320