a(n) is the least prime of the form 2^j*3^k - 1, j > 0, k > 0, j + k = n. a(n) = 0 if no such prime exists.

A337437

a(n) is the least prime of the form 2^j*3^k - 1, j > 0, k > 0, j + k = n. a(n) = 0 if no such prime exists.

Terms

    a(0) =5a(1) =11a(2) =23a(3) =47a(4) =0a(5) =191a(6) =383a(7) =1151a(8) =0a(9) =6911a(10) =6143a(11) =27647a(12) =0a(13) =73727a(14) =497663a(15) =294911a(16) =0a(17) =786431a(18) =17915903a(19) =10616831a(20) =0a(21) =18874367a(22) =188286357653a(23) =169869311a(24) =0a(25) =39182082047a(26) =10319560703a(27) =4076863487a(28) =0a(29) =7247757311

External references