187663465045domain: NAppears in sequencesa(n) = a(n-3) - 5*a(n-2) + 5*a(n-1), a(0) = 1, a(1) = 3, a(2) = 10.at n=20A102871a(n) = A002531(n)*A002531(n+1).at n=20A146983Indices of centered triangular numbers (A005448) which are also hexagonal numbers (A000384).at n=10A254284