A171183 Numbers n such that sigmawt(n) = sigmawt(n+1), where sigmawt(n) is the sum of the divisors of n weighted by divisor multiplicity in n.

14, 957, 1334, 1634, 2402, 2685, 20145, 33998, 42818, 74918, 79826, 79833, 84134, 111506, 122073, 138237, 147454, 166934, 201597, 274533, 289454, 347738, 383594, 416577, 440013, 544334, 605985, 649154, 655005, 1060802, 1642154, 1674513

Offset

1,1

Links

Ray Chandler, Table of n, a(n) for n=1..200

Mathematica

divmult[d_, n_] := Module[{output, i}, If[d == 1, output = 1, If[d == n, output = 1, i = 0; While[Mod[n, d^(i + 1)] == 0, i = i + 1]; output = i]]; output]; dmt[n_] := Module[{divs, l}, divs = Divisors[n]; l = Length[divs]; Sum[divmult[divs[[i]], n]*divs[[i]], {i, 1, l}]]; l = {}; Do[If[dmt[i] == dmt[i + 1], l = Append[l, i]], {i, 1, 10^6}]; l

Crossrefs

See A168512 for definition of divisor multiplicity.

Sequence in context: A199651 A241110 A055152 * A064729 A189304 A123178

Adjacent sequences: A171180 A171181 A171182 * A171184 A171185 A171186

Keyword

nonn

Author

Joseph L. Pe, Dec 05 2009

Extensions

Extended by Ray Chandler, Dec 08 2009

Status

approved