Numbers k such that k and k+1 have the same number of distinct prime divisors.

Terms

a(0) =2a(1) =3a(2) =4a(3) =7a(4) =8a(5) =14a(6) =16a(7) =20a(8) =21a(9) =31a(10) =33a(11) =34a(12) =35a(13) =38a(14) =39a(15) =44a(16) =45a(17) =50a(18) =51a(19) =54a(20) =55a(21) =56a(22) =57a(23) =62a(24) =68a(25) =74a(26) =75a(27) =76a(28) =85a(29) =86