Triangular numbers k such that phi(k) is a square number, where phi(k) is the Euler totient function (A000010).
A287473
Triangular numbers k such that phi(k) is a square number, where phi(k) is the Euler totient function (A000010).
Terms
- a(0) =1a(1) =10a(2) =136a(3) =630a(4) =2016a(5) =7875a(6) =9180a(7) =18915a(8) =32896a(9) =37128a(10) =46056a(11) =58311a(12) =66430a(13) =103740a(14) =131841a(15) =198135a(16) =225456a(17) =301476a(18) =323610a(19) =332520a(20) =408156a(21) =499500a(22) =738720a(23) =786885a(24) =839160a(25) =862641a(26) =922761a(27) =924120a(28) =1065070a(29) =1079715
External references
- oeis: A287473