a(n) = 0 if n <= 2; thereafter a(n) = A238827(n) + A238830(n-2).

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =1a(6) =3a(7) =8a(8) =21a(9) =49a(10) =124a(11) =295a(12) =735a(13) =1789a(14) =4428a(15) =10874a(16) =26836a(17) =66062a(18) =162838a(19) =401081a(20) =988225a(21) =2434388a(22) =5997403a(23) =14774547a(24) =36397880a(25) =89667011a(26) =220898267a(27) =544190131a(28) =1340632638a(29) =3302695932