Indices n of primes p(n), p(n+4) such that p(n)-1 and p(n+4)-1 have the same largest prime factor.

Terms

a(0) =3a(1) =4a(2) =8a(3) =10a(4) =21a(5) =25a(6) =54a(7) =67a(8) =122a(9) =304a(10) =436a(11) =640a(12) =647a(13) =1106a(14) =1917a(15) =2292a(16) =3622a(17) =3783a(18) =10285a(19) =10600a(20) =14785a(21) =20211a(22) =21804a(23) =137507a(24) =383436a(25) =413254a(26) =662294a(27) =766759a(28) =841376a(29) =880622