A097037 Initial values for iteration of A063919(x) function such that iteration ends in a 2-cycle, i.e., "attracted" by unitary amicable numbers, A063991.

102, 114, 126, 388, 436, 484, 812, 866, 1020, 1036, 1040, 1116, 1140, 1196, 1260, 1380, 1500, 1524, 1532, 1552, 1618, 1644, 1716, 1724, 1726, 1744, 1916, 2020, 2066, 2068, 2324, 2368, 2386, 2486, 2592, 2684, 2880, 2924, 3032, 3098, 3120, 3124, 3136

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..1000

Example

n = 866: list = {866, 436, 114, 126, 114} ending in 2-cycle of [114, 126].

Mathematica

s[n_] := If[n > 1, Times @@ (1 + Power @@@ FactorInteger[n]) - n, 0]; useq[n_] := Most[NestWhileList[s, n, UnsameQ, All]]; amiQ[k_] := Module[{s1 = s[k]}, s1 != k && s[s1] == k]; aQ[n_] := amiQ[Last[useq[n]]]; Select[Range[5000], aQ] (* Amiram Eldar, Apr 06 2019 *)

Crossrefs

Cf. A002827, A063919, A063991, A097024, A097030-A097036.

Sequence in context: A354710 A031413 A127665 * A035480 A379162 A181986

Adjacent sequences: A097034 A097035 A097036 * A097038 A097039 A097040

Keyword

nonn

Author

Labos Elemer, Aug 30 2004

Status

approved