Numbers having period-21 7-digitized sequences.

Terms

a(0) =19a(1) =34a(2) =43a(3) =91a(4) =109a(5) =127a(6) =172a(7) =190a(8) =217a(9) =247a(10) =271a(11) =274a(12) =304a(13) =334a(14) =340a(15) =343a(16) =349a(17) =388a(18) =394a(19) =403a(20) =427a(21) =430a(22) =433a(23) =439a(24) =472a(25) =493a(26) =568a(27) =586a(28) =658a(29) =685