a(n) is the least n-digit number whose k-th digit is prime if k is prime, composite if k is composite, and 1 if k=1.

A113574

a(n) is the least n-digit number whose k-th digit is prime if k is prime, composite if k is composite, and 1 if k=1.

Terms

    a(0) =1a(1) =12a(2) =122a(3) =1224a(4) =12242a(5) =122424a(6) =1224242a(7) =12242424a(8) =122424244a(9) =1224242444a(10) =12242424442a(11) =122424244424

External references