Numbers whose square is the sum of distinct double factorials (A006882).

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =5a(5) =7a(6) =8a(7) =11a(8) =13a(9) =20a(10) =21a(11) =31a(12) =38a(13) =62a(14) =63a(15) =65a(16) =66a(17) =70a(18) =72a(19) =102a(20) =107a(21) =109a(22) =120a(23) =125a(24) =217a(25) =218a(26) =238a(27) =240a(28) =373a(29) =382