A077085 Initial values such that if A077080(x)=phi(sigma(x)+phi(x)) is started at these numbers then the sequence does not converge.

534, 556, 557, 580, 624, 702, 710, 738, 739, 740, 748, 784, 789, 822, 823, 841, 852, 853, 900, 912, 913, 916, 924, 931, 938, 960, 961, 962, 1020, 1021, 1029, 1032, 1033, 1034, 1065, 1089, 1092, 1093, 1098, 1126, 1136

Offset: 1

Author

Labos Elemer, Oct 28 2002

Keywords

• nonn

Comments

These terms are only conjectures.

These terms survive 1000 iterations. - Sean A. Irvine, May 05 2025

Crossrefs

Cf. A000010, A000203, A065387, A077080, A077081, A077082, A077083, A077084.

Programs

Mathematica

f[x_] := EulerPhi[DivisorSigma[1, x]+EulerPhi[x]] Do[s=Part[NestList[f, n, 100], 100]; If[Greater[s, 10000000], Print[{n, s}]], {n, 1, 10000}]