a(n) = T(5,n), array T given by A047858.

Terms

a(0) =1a(1) =7a(2) =20a(3) =48a(4) =108a(5) =236a(6) =508a(7) =1084a(8) =2300a(9) =4860a(10) =10236a(11) =21500a(12) =45052a(13) =94204a(14) =196604a(15) =409596a(16) =851964a(17) =1769468a(18) =3670012a(19) =7602172a(20) =15728636a(21) =32505852a(22) =67108860a(23) =138412028a(24) =285212668a(25) =587202556a(26) =1207959548a(27) =2483027964a(28) =5100273660a(29) =10468982780