OFFSET
1,1
COMMENTS
Starting the sequence at a(1)=1 instead would lead to a(n) = n for all positive integers n.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
MATHEMATICA
a = {2}; Do[i = a[[ -1]] + 1; While[ ! Length[Divisors[i]] == Length[Divisors[n]], i++ ]; AppendTo[a, i], {n, 2, 80}]; a (* Stefan Steinerberger, Apr 26 2008 *)
nxt[{a_, n_}]:=Module[{k=a+1, div=DivisorSigma[0, n+1]}, While[div != DivisorSigma[ 0, k], k++]; {k, n+1}]; Transpose[NestList[nxt, {2, 1}, 60]] [[1]] (* Harvey P. Dale, May 28 2014 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Apr 24 2008
EXTENSIONS
More terms from Stefan Steinerberger, Apr 26 2008
STATUS
approved