Left-hand half of triangle A297193.

Terms

a(0) =1a(1) =1a(2) =4a(3) =1a(4) =8a(5) =17a(6) =1a(7) =12a(8) =49a(9) =80a(10) =1a(11) =16a(12) =97a(13) =280a(14) =401a(15) =1a(16) =20a(17) =161a(18) =672a(19) =1569a(20) =2084a(21) =1a(22) =24a(23) =241a(24) =1320a(25) =4321a(26) =8752a(27) =11073a(28) =1a(29) =28