A171666 Numbers n such that n, n+1 and n+2 have the same number of divisors, and that number of divisors is larger than 4.
230, 242, 243, 374, 603, 663, 902, 1105, 1274, 1309, 1334, 1832, 1885, 1924, 2013, 2054, 2133, 2264, 2343, 2504, 2523, 2665, 2696, 2936, 3110, 3655, 3656, 3729, 4203, 4401, 4503, 4504, 4614, 4669, 4695, 4807, 4923, 5133, 5862, 5943, 5944, 6054, 6061
Offset: 1
Keywords
Links
- Harvey P. Dale, Table of n, a(n) for n = 1..1000
Programs
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Mathematica
f[n_]:=Length[Divisors[n]]; lst={};Do[If[f[n]==f[n+1]==f[n+2]&&f[n]>4,AppendTo[lst,n]],{n,8!}];lst Flatten[Position[Partition[DivisorSigma[0,Range[7000]],3,1],?(Length[ Union[#]]==1&&#[[1]]>4&),{1},Heads->False]] (* _Harvey P. Dale, Jul 20 2014 *) SequencePosition[Table[If[DivisorSigma[0,n]>4,DivisorSigma[0,n],n],{n,6100}],{x_,x_,x_}][[All,1]] (* Harvey P. Dale, Nov 15 2021 *)