Number of length n 1..(1+2) arrays with no leading partial sum equal to a prime.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =4a(5) =6a(6) =11a(7) =20a(8) =33a(9) =62a(10) =135a(11) =317a(12) =692a(13) =1345a(14) =2651a(15) =5741a(16) =12576a(17) =25825a(18) =49270a(19) =90118a(20) =168115a(21) =340003a(22) =751400a(23) =1741713a(24) =4057301a(25) =9232683a(26) =20184851a(27) =42473752a(28) =87925348a(29) =183030469