a(n) = A000931(n)^2.

Terms

a(0) =1a(1) =0a(2) =0a(3) =1a(4) =0a(5) =1a(6) =1a(7) =1a(8) =4a(9) =4a(10) =9a(11) =16a(12) =25a(13) =49a(14) =81a(15) =144a(16) =256a(17) =441a(18) =784a(19) =1369a(20) =2401a(21) =4225a(22) =7396a(23) =12996a(24) =22801a(25) =40000a(26) =70225a(27) =123201a(28) =216225a(29) =379456