42618domain: NAppears in sequencesNumbers k such that 2^(2k+1) + 2^(k+1) + 1 is prime.at n=14A006599Number of 2 X 2 matrices with all elements in {0,1,...,n} and determinant >=n.at n=17A210366Fixed points in A336957.at n=25A338050G.f. A(x) satisfies A(x) = 1 + x*A(x)*abs( 1/A(x)^2 ).at n=12A380710