1336140domain: 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=11A102871a(n) = -a(n-1)+4*a(n-2)+4*a(n-3)-a(n-4)-a(n-5).at n=24A107401Indices of centered triangular numbers (A005448) which are also hexagonal numbers (A000384).at n=5A254284