Composite n such that phi(n+4) = phi(n)+4.

Terms

a(0) =12a(1) =18a(2) =24a(3) =28a(4) =36a(5) =40a(6) =66a(7) =88a(8) =124a(9) =184a(10) =232a(11) =328a(12) =424a(13) =508a(14) =664a(15) =712a(16) =904a(17) =1048a(18) =1384a(19) =1432a(20) =1528a(21) =1864a(22) =1912a(23) =2008a(24) =2248a(25) =2344a(26) =2586a(27) =2872a(28) =3352a(29) =3448