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a(n) = n^2 + phi(n).
1

%I #10 Sep 08 2022 08:46:14

%S 2,5,11,18,29,38,55,68,87,104,131,148,181,202,233,264,305,330,379,408,

%T 453,494,551,584,645,688,747,796,869,908,991,1040,1109,1172,1249,1308,

%U 1405,1462,1545,1616,1721,1776,1891,1956,2049,2138,2255,2320,2443,2520

%N a(n) = n^2 + phi(n).

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

%e a(5) = 29, because phi(5) = 4 and 5^2 + 4 = 29.

%t Table[n^2 + EulerPhi[n], {n, 50}]

%o (Magma) [n^2+EulerPhi(n): n in [1..50]];

%o (PARI) a(n) = n^2 + eulerphi(n); \\ _Altug Alkan_, Nov 24 2015

%Y Cf. A000010, A000290, A258434.

%K nonn,easy

%O 1,1

%A _Vincenzo Librandi_, Nov 24 2015