42730domain: NAppears in sequencesNumbers k such that 8*3^k - 1 is prime.at n=18A005541McKay-Thompson series of class 36C for Monster.at n=51A058646Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 1 X 3 which is flat, i.e., with all blocks in parallel position.at n=6A123772