G.f. satisfies A(x) = 1/(1-x) + x^4*A(x)^4.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =5a(6) =11a(7) =21a(8) =40a(9) =85a(10) =197a(11) =457a(12) =1028a(13) =2289a(14) =5193a(15) =12069a(16) =28338a(17) =66445a(18) =155563a(19) =365701a(20) =865815a(21) =2061133a(22) =4919431a(23) =11758741a(24) =28165412a(25) =67657225a(26) =162977081a(27) =393445865a(28) =951438682a(29) =2304494349