a(1)=1; a(n)=a(n-1)*(number of decimal digits of a(n-1))+1.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =5a(5) =6a(6) =7a(7) =8a(8) =9a(9) =10a(10) =21a(11) =43a(12) =87a(13) =175a(14) =526a(15) =1579a(16) =6317a(17) =25269a(18) =126346a(19) =758077a(20) =4548463a(21) =31839242a(22) =254713937a(23) =2292425434a(24) =22924254341a(25) =252166797752