A395402 - OEIS

%I #6 Apr 22 2026 01:04:17

%S 352,513,532,792,1197,3325,16093,20577,22477,38437,70357,111853,

%T 127813,182077,223573,245917,293797,373597,462973,494893,597037,

%U 670453,708757,830053,916237,1053493,1251397,1356733,1410997,1522717,1580173,1698277,2145157,2282413,2496277,2569693,2952733,3032533

%N Numbers k such that sigma(k) = psi(k) + tau(k)^2 + Omega(k)^2.

%e 352 is a term since sigma(352) = 756 = 576 + 12^2 + 6^2 = psi(352) + tau(352)^2 + Omega(352)^2.

%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)) + numdiv(f)^2 + bigomega(f)^2; } \\ _Amiram Eldar_, Apr 21 2026

%Y Cf. A000005, A000203, A001615, A001222, A394658.

%K nonn

%O 1,1

%A _S. I. Dimitrov_, Apr 21 2026