27542domain: NAppears in sequencesRecord gaps between Chebyshev primes (of index 1).at n=14A196672Number of 0..n arrays x(0..6) of 7 elements with zero 4th differences.at n=36A200274Total number of torsion-free congruence subgroups of PSL(2,Z) of genus n.at n=21A258696Numbers k such that (8*10^k - 83)/3 is prime.at n=18A293851