Earliest positive integer having embedded exactly k distinct primes.

Terms

a(0) =1a(1) =2a(2) =13a(3) =23a(4) =113a(5) =137a(6) =1131a(7) =1137a(8) =1373a(9) =11379a(10) =11317a(11) =23719a(12) =111317a(13) =113171a(14) =211373a(15) =1113171a(16) =1113173a(17) =1317971a(18) =2313797a(19) =11131733a(20) =11317971a(21) =13179719a(22) =82337397a(23) =52313797a(24) =113179719a(25) =113733797a(26) =523137971a(27) =1113173331a(28) =1131797193a(29) =1797193373