82779domain: NAppears in sequencesNumbers k such that 6*3^k + 1 is prime.at n=31A216888Number of (1+1) X (n+1) arrays of permutations of 0..n*2+1 filled by rows with each element moved a city block distance of 0 or 2, and rows and columns in increasing lexicographic order.at n=18A263603