Numbers k such that phi(k) = phi(k+4), with Euler's totient function phi = A000010.

Terms

a(0) =8a(1) =14a(2) =16a(3) =20a(4) =35a(5) =52a(6) =64a(7) =91a(8) =140a(9) =148a(10) =244a(11) =292a(12) =403a(13) =455a(14) =616a(15) =628a(16) =772a(17) =801a(18) =1011a(19) =1024a(20) =1108a(21) =1144a(22) =1252a(23) =1270a(24) =1295a(25) =1456a(26) =1588a(27) =1684a(28) =1820a(29) =1828