beastly palindromic prime | Beelphegor prime

A Belphegor prime (also known as a Beelphegor prime) is a prime Belphegor number, i.e., a palindromic prime of the form 1(0...)666(0...)1. The first few Belphegor primes are the Belphegor numbers B_n = 10^(2n + 4) + 666·10^(n + 1) + 1 with n = 0, 13, 42, 506, 608, 2472, 2623, 28291, 181298, ... (OEIS A232448). Shifting this sequence by one gives 1, 14, 43, 507, 609, ... (OEIS A156166).

beast number | Belphegor number | integer sequence primes | palindromic prime