Spiral sieve using Fibonacci numbers.

Terms

a(0) =1a(1) =2a(2) =4a(3) =7a(4) =9a(5) =17a(6) =25a(7) =46a(8) =51a(9) =83a(10) =158a(11) =233a(12) =365a(13) =568a(14) =967a(15) =1645a(16) =2468a(17) =4077a(18) =6767a(19) =10792a(20) =17801a(21) =28635a(22) =46298a(23) =75403a(24) =121165a(25) =196524a(26) =318947a(27) =514667a(28) =832362a(29) =1346093