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

Terms

a(0) =3a(1) =45a(2) =6450a(3) =18000a(4) =22785a(5) =41790a(6) =54180a(7) =77385a(8) =87675a(9) =98385a(10) =103005a(11) =104520a(12) =151515a(13) =187005a(14) =210210a(15) =244590a(16) =256620a(17) =320775a(18) =329175a(19) =354795a(20) =382875a(21) =387975a(22) =431385a(23) =495540a(24) =509355a(25) =528510a(26) =632775a(27) =763815a(28) =804870a(29) =810540