Floor[ X/Y], where X = concatenation of the primes and Y = concatenation of natural numbers.

Terms

a(0) =2a(1) =1a(2) =1a(3) =1a(4) =19a(5) =190a(6) =1909a(7) =19092a(8) =190926a(9) =190926a(10) =190926a(11) =190926a(12) =190926a(13) =190926a(14) =190926a(15) =190926a(16) =190926a(17) =190926a(18) =190926a(19) =190926a(20) =190926a(21) =190926a(22) =190926a(23) =190926a(24) =190926a(25) =1909260a(26) =19092601a(27) =190926018a(28) =1909260182a(29) =19092601827