A290146 Records of the maxima of the unitary aliquot sequences of the numbers in A290145.

54, 90, 126, 162, 198, 378, 4950, 12978, 82278, 94218606, 8855754260391450, 645856907610421353834, 1350253136232108126126, 27709820863862780667438

Offset: 1

Author

Amiram Eldar, Jul 21 2017

Keywords

• nonn
• more

Examples

			The unitary aliquot sequence of 174 is: 174, 186, 198, 162, 84, 76, 24, 12, 8, 1. Its maximum is 198 which larger than the maxima of all the aliquot sequences of the numbers below 174.
		

Crossrefs

Cf. A098008, A098009, A098010, A290145.

Programs

Mathematica

usigma[n_] := If[n == 1, 1, Times @@ (1 + Power @@@ FactorInteger[n])];
g[n_] := If[n > 0, usigma[n] - n, 0]; f[n_] := NestWhileList[g, n, UnsameQ, All]; a = -1; rec = {}; Do[b = Length[f[n]] - 2; If[b > a, a = b; AppendTo[rec, b ]], {n, 10^6}] ; rec (* after Giovanni Resta at A034448 & Robert G. Wilson v at A098009 *)