63731domain: NAppears in sequencesQuotient of the decimal representation of concatenated twin primes divided by 3.at n=13A129908a(n) = 100*n^2 - 151*n + 57.at n=25A157626a(n) = 3^n + 2^(3*n + 1) - 2^(2*n + 1).at n=4A377641Numbers k such that A224787(k) - k is a square.at n=45A385238