126801domain: NAppears in sequencesNumbers n such that n-1, n and n+1 can be expressed as a sum of 2 squares in at least 2 ways.at n=27A091459G.f. A(x,y) satisfies 1/x = Sum_{n=-oo..+oo} A(x,y)^n * (A(x,y)^n + y)^(n+1), as a triangle of coefficients T(n,k) of x^n*y^k in A(x,y), read by rows.at n=50A379200