Numbers which are products of repunits.

Terms

a(0) =1a(1) =11a(2) =111a(3) =121a(4) =1111a(5) =1221a(6) =1331a(7) =11111a(8) =12221a(9) =12321a(10) =13431a(11) =14641a(12) =111111a(13) =122221a(14) =123321a(15) =134431a(16) =135531a(17) =147741a(18) =161051a(19) =1111111a(20) =1222221a(21) =1233321a(22) =1234321a(23) =1344431a(24) =1356531a(25) =1367631a(26) =1478741a(27) =1490841a(28) =1625151a(29) =1771561