Expansion of Sum_{k>=0} (x * (1 + k*x^2))^k.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =5a(5) =10a(6) =21a(7) =53a(8) =133a(9) =327a(10) =861a(11) =2361a(12) =6469a(13) =18168a(14) =52757a(15) =155221a(16) =463077a(17) =1412656a(18) =4379917a(19) =13747504a(20) =43834213a(21) =141866555a(22) =464650309a(23) =1541008295a(24) =5176660997a(25) =17586913779a(26) =60400627453a(27) =209746820056a(28) =735953607173