Smallest number having exactly n divisors ending with 3 or 7.

Terms

a(0) =3a(1) =21a(2) =63a(3) =189a(4) =567a(5) =693a(6) =3969a(7) =2079a(8) =5733a(9) =6237a(10) =413343a(11) =9009a(12) =74529a(13) =43659a(14) =51597a(15) =27027a(16) =1750329a(17) =63063a(18) =26040609a(19) =81081a(20) =464373a(21) =670761a(22) =219667417263a(23) =153153a(24) =2528253a(25) =819819a(26) =693693a(27) =729729a(29) =567567a(30) =6036849