a(n) is the number of n-digit terms in A383779.

Terms

a(0) =4a(1) =12a(2) =46a(3) =103a(4) =396a(5) =717a(6) =2451a(7) =3929a(8) =11803a(9) =17202a(10) =46916a(11) =62668a(12) =157138a(13) =197114a(14) =458064a(15) =541267a(16) =1180018a(17) =1323543a(18) =2718398a(19) =2915696a(20) =5675113a(21) =5839596a(22) =10821575a(23) =10724938a(24) =18983655a(25) =18174231a(26) =30856021a(27) =28608908a(28) =46708476a(29) =42036009