a(n) = ceiling(Sum_{i=1..n-1} a(i)/4) for n >= 2 starting with a(1) = 1.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =2a(6) =2a(7) =3a(8) =3a(9) =4a(10) =5a(11) =6a(12) =8a(13) =10a(14) =12a(15) =15a(16) =19a(17) =24a(18) =30a(19) =37a(20) =47a(21) =58a(22) =73a(23) =91a(24) =114a(25) =142a(26) =178a(27) =222a(28) =278a(29) =347