A065388 - OEIS

%I #13 Aug 18 2024 17:51:15

%S 2,4,6,9,10,14,19,22,32,39,45,50,68,80,103,106,108,140,144,184,219,

%T 248,258,284,316,392,451,528,594,624,672,808,816,915,948,955,1088,

%U 1266,1440,1640,1704,1824,1843,2020,2031,2176,2208,2610,3072,3304,3512,3888

%N Record values for sigma(m) + phi(m): sum of sigma and totient is larger than for any previous number.

%H Harry J. Smith, <a href="/A065388/b065388.txt">Table of n, a(n) for n=1..500</a>

%F a(n) = sigma(A015702(n)) + phi(A015702(n));

%F a(n) = A000203(A015702(n)) + A000010(A015702(n)).

%o (PARI) { n=r=0; for (m=1, 10^9, x=sigma(m) + eulerphi(m); if (x > r, r=x; write("b065388.txt", n++, " ", x); if (n==500, return)) ) } \\ _Harry J. Smith_, Oct 17 2009

%Y Cf. A000010, A000203, A065387, A015702.

%K nonn

%O 1,1

%A _Labos Elemer_, Nov 05 2001