Multiples of 7.

Terms

a(0) =0a(1) =7a(2) =14a(3) =21a(4) =28a(5) =35a(6) =42a(7) =49a(8) =56a(9) =63a(10) =70a(11) =77a(12) =84a(13) =91a(14) =98a(15) =105a(16) =112a(17) =119a(18) =126a(19) =133a(20) =140a(21) =147a(22) =154a(23) =161a(24) =168a(25) =175a(26) =182a(27) =189a(28) =196a(29) =203