Numbers k such that 2k+1, 4k+1, 6k+1, 8k+1 and 10k+1 are primes.

Terms

a(0) =5415a(1) =12705a(2) =13020a(3) =44370a(4) =82950a(5) =98280a(6) =105525a(7) =112200a(8) =115140a(9) =123855a(10) =134250a(11) =134460a(12) =187740a(13) =188745a(14) =210165a(15) =225705a(16) =247170a(17) =256410a(18) =296310a(19) =302085a(20) =367875a(21) =375645a(22) =382890a(23) =399585a(24) =404040a(25) =476340a(26) =487830a(27) =526845a(28) =532095a(29) =566430