OFFSET
1,2
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..200
MATHEMATICA
Module[{nn=120, in, len}, in=Select[Range[nn], DivisorSigma[1, #]!=2#&]; len= Floor[x/.Last[Solve[(x(x+1))/2==Length[in]]]]; FromDigits[Flatten[ IntegerDigits/@ #]]&/@TakeList[in, Range[len]]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Mar 01 2020 *)
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Omar E. Pol, Nov 12 2007
STATUS
approved