44598domain: NAppears in sequencesHow many more primes than irreducible GF(2)[X] polynomials there are in range [0,2^n].at n=21A091231Number of base 18 n-digit numbers with adjacent digits differing by two or less.at n=6A126405a(n) = n*(n^3 + 2*n^2 - 5*n + 10)/8.at n=24A294259