Numbers k for which phi(k^2) = phi(k-1) * phi(k+1).

Terms

a(0) =2a(1) =4a(2) =16a(3) =256a(4) =976a(5) =3256a(6) =5188a(7) =11716a(8) =13366a(9) =22936a(10) =65536a(11) =307396a(12) =491536a(13) =589408a(14) =983776a(15) =1659586a(16) =2822716a(17) =3137356a(18) =5577826a(19) =6475456a(20) =7378372a(21) =8698096a(22) =10798726a(23) =32235736a(24) =37797436a(25) =39220126a(26) =39285436a(27) =51555136a(28) =52077196a(29) =56992552