# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a079535 Showing 1-1 of 1 %I A079535 #10 Sep 08 2022 08:45:08 %S A079535 0,0,1,2,3,2,5,8,9,6,9,12,11,10,17,24,15,18,17,28,27,18,21,40,35,22, %T A079535 45,44,27,34,29,64,47,30,61,72,35,34,57,88,39,54,41,76,99,42,45,112, %U A079535 77,70,77,92,51,90,105,136,87,54,57,132,59,58,153,160,127,94,65,124,107,122,69 %N A079535 a(n) = phi(n)*d(n) - n. %C A079535 It is known that a(n) >= 0. %D A079535 D. S. Mitrinovic et al., Handbook of Number Theory, Kluwer, p. 10. %H A079535 G. C. Greubel, Table of n, a(n) for n = 1..10000 %t A079535 Table[EulerPhi[n]*DivisorSigma[0, n] - n, {n, 1, 80}] (* _G. C. Greubel_, Jan 14 2019 *) %o A079535 (PARI) vector(80, n, eulerphi(n)*sigma(n,0) - n) \\ _G. C. Greubel_, Jan 14 2019 %o A079535 (Magma) [EulerPhi(n)*DivisorSigma(0,n) - n: n in [1..80]]; // _G. C. Greubel_, Jan 14 2019 %o A079535 (Sage) [euler_phi(n)*sigma(n, 0) - n for n in (1..80)] # _G. C. Greubel_, Jan 14 2019 %Y A079535 Cf. A000010, A000005, A062355. %K A079535 nonn %O A079535 1,4 %A A079535 _N. J. A. Sloane_, Jan 23 2003 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE