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A258434 n^2 - phi(n). 2

%I

%S 0,3,7,14,21,34,43,60,75,96,111,140,157,190,217,248,273,318,343,392,

%T 429,474,507,568,605,664,711,772,813,892,931,1008,1069,1140,1201,1284,

%U 1333,1426,1497,1584,1641,1752,1807,1916,2001,2094,2163,2288

%N n^2 - phi(n).

%F a(n) = A000290(n) - A000010(n).

%F For p prime, a(p) = A002061(p); A119959 is a subsequence. - _Michel Marcus_, Jun 06 2015

%e a(5) = 21, since 5^2 = 25 and phi(5) = 4.

%t Table[n^2 - EulerPhi[n], {n, 200}]

%o (PARI) vector(50, n, n^2-eulerphi(n)) \\ _Michel Marcus_, May 30 2015

%o (MAGMA) [n^2 - EulerPhi(n): n in [1..60]]; // _Vincenzo Librandi_, Jun 03 2015

%Y Cf. A000290, A000010.

%K nonn,easy

%O 1,2

%A _Carlos Eduardo Olivieri_, May 30 2015

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Last modified July 26 10:21 EDT 2021. Contains 346294 sequences. (Running on oeis4.)