Numbers k such that 1 + binomial(k,j) is prime for only 2 values of j (0 <= j <= k).

Terms

a(0) =1a(1) =3a(2) =7a(3) =15a(4) =23a(5) =31a(6) =59a(7) =63a(8) =67a(9) =81a(10) =84a(11) =93a(12) =95a(13) =127a(14) =157a(15) =170a(16) =214a(17) =239a(18) =253a(19) =255a(20) =313a(21) =470a(22) =511a(23) =622a(24) =694a(25) =1010a(26) =1023a(27) =1098a(28) =1691a(29) =2047