Number of Ramanujan primes <= 2^n.

Terms

a(0) =0a(1) =1a(2) =1a(3) =1a(4) =2a(5) =4a(6) =7a(7) =13a(8) =23a(9) =42a(10) =75a(11) =137a(12) =255a(13) =463a(14) =872a(15) =1612a(16) =3030a(17) =5706a(18) =10749a(19) =20387a(20) =38635a(21) =73584a(22) =140336a(23) =268216a(24) =513705a(25) =985818a(26) =1894120a(27) =3645744a(28) =7027290a(29) =13561906