Numbers of form 7^i*10^j, with i, j >= 0.

Terms

a(0) =1a(1) =7a(2) =10a(3) =49a(4) =70a(5) =100a(6) =343a(7) =490a(8) =700a(9) =1000a(10) =2401a(11) =3430a(12) =4900a(13) =7000a(14) =10000a(15) =16807a(16) =24010a(17) =34300a(18) =49000a(19) =70000a(20) =100000a(21) =117649a(22) =168070a(23) =240100a(24) =343000a(25) =490000a(26) =700000a(27) =823543a(28) =1000000a(29) =1176490