Number of subsets of {1,.., n} containing at least one twin prime pair.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =8a(5) =16a(6) =48a(7) =96a(8) =192a(9) =384a(10) =768a(11) =1536a(12) =4352a(13) =8704a(14) =17408a(15) =34816a(16) =69632a(17) =139264a(18) =339968a(19) =679936a(20) =1359872a(21) =2719744a(22) =5439488a(23) =10878976a(24) =21757952a(25) =43515904a(26) =87031808a(27) =174063616a(28) =348127232a(29) =696254464