Numbers n such that the sum of the Euler totient functions of integers up to n is a square.

A130697

Numbers n such that the sum of the Euler totient functions of integers up to n is a square.

Terms

    a(0) =1a(1) =3a(2) =14a(3) =32a(4) =54a(5) =1458a(6) =3765a(7) =5343a(8) =10342a(9) =57918a(10) =72432a(11) =134072a(12) =1103584a(13) =4984175a(14) =9191040a(15) =18399460a(16) =49034273a(17) =176485286a(18) =423360893a(19) =1432766906a(20) =62342171276a(21) =433015422290

External references