a(n) = ceiling(n*phi^4), where phi is the golden ratio, A001622.

Terms

a(0) =0a(1) =7a(2) =14a(3) =21a(4) =28a(5) =35a(6) =42a(7) =48a(8) =55a(9) =62a(10) =69a(11) =76a(12) =83a(13) =90a(14) =96a(15) =103a(16) =110a(17) =117a(18) =124a(19) =131a(20) =138a(21) =144a(22) =151a(23) =158a(24) =165a(25) =172a(26) =179a(27) =186a(28) =192a(29) =199