a(1) = 1, a(2n) is the smallest composite number == 1 mod (a(2n-1)) and a(2n+1) is the smallest prime == 1 (mod a(2n)).
A075341
a(1) = 1, a(2n) is the smallest composite number == 1 mod (a(2n-1)) and a(2n+1) is the smallest prime == 1 (mod a(2n)).
Terms
- a(0) =1a(1) =4a(2) =5a(3) =6a(4) =7a(5) =8a(6) =17a(7) =18a(8) =19a(9) =20a(10) =41a(11) =42a(12) =43a(13) =44a(14) =89a(15) =90a(16) =181a(17) =182a(18) =547a(19) =548a(20) =1097a(21) =1098a(22) =7687a(23) =7688a(24) =15377a(25) =15378a(26) =30757a(27) =30758a(28) =276823a(29) =276824
External references
- oeis: A075341