Numbers k such that 1*k + 1, 3*k + 1, 9*k + 1, 27*k + 1, 81*k + 1 are all primes.

Terms

a(0) =60a(1) =760a(2) =2440a(3) =5800a(4) =8680a(5) =17350a(6) =21840a(7) =27010a(8) =40030a(9) =84060a(10) =108010a(11) =109890a(12) =131110a(13) =222940a(14) =277750a(15) =309120a(16) =313030a(17) =334170a(18) =346140a(19) =348660a(20) =356500a(21) =358330a(22) =387160a(23) =419230a(24) =470880a(25) =553410a(26) =578820a(27) =604030a(28) =683340a(29) =729820