A393529 - OEIS

%I #11 Feb 23 2026 22:38:57

%S 1631560,2074884,2568804,2642892,2720508,3585736,5008812,5265444,

%T 5283460,5810628,5820324,5848068,5945172,5952108,6185032,6977300,

%U 6991356,7497816,7524588,7706020,7827252,8636244,10070536,10828236,11721220,12276708,12681204,13296136,14153532,14913220,16562260,17152072

%N Numbers k such that sigma(k) = psi(k) + phi(k) + Omega(k)^7.

%H Michael S. Branicky, <a href="/A393529/b393529.txt">Table of n, a(n) for n = 1..240</a>

%e 1631560 is a term since sigma(1631560) = 4196160 = 3356928 + 559296 + 6^7 = psi(1631560) + phi(1631560) + Omega(1631560)^7.

%o (PARI) isok(k) = {my(f = factor(k)); sigma(f) == prod(i=1, #f~, (f[i, 1]+1) * f[i, 1]^(f[i, 2]-1)) + eulerphi(f) + bigomega(f)^7;} \\ _Amiram Eldar_, Feb 19 2026

%Y Cf. A000203, A001615, A000010, A001222, A390049, A393229, A393230, A393425, A391448, A393528.

%K nonn

%O 1,1

%A _S. I. Dimitrov_, Feb 18 2026