a(1) = 2; k(1) = 0; for n > 1: k(n) = smallest number j >= k(n-1) such that 2*a(n-1) + j is prime; a(n) = 2*a(n-1) + k(n).
A105120
a(1) = 2; k(1) = 0; for n > 1: k(n) = smallest number j >= k(n-1) such that 2*a(n-1) + j is prime; a(n) = 2*a(n-1) + k(n).
Terms
- a(0) =2a(1) =5a(2) =11a(3) =23a(4) =47a(5) =97a(6) =197a(7) =397a(8) =797a(9) =1597a(10) =3203a(11) =6421a(12) =12889a(13) =25841a(14) =51749a(15) =103567a(16) =207227a(17) =414553a(18) =829211a(19) =1658533a(20) =3317177a(21) =6634469a(22) =13269059a(23) =26538257a(24) =53076679a(25) =106153547a(26) =212307299a(27) =424614829a(28) =849229907a(29) =1698460067
External references
- oeis: A105120