OFFSET
1,2
COMMENTS
Choose the first number not leading to a contradiction.
EXAMPLE
Each of the three pairwise sums of the subset {29, 41, 281} is the product of three distinct prime factors: {2*5*7, 2*5*31, 2*7*23}.
MAPLE
with(numtheory):nn:=200000:T:=array(1..nn): U:=array(1..nn): for p from 1 to
nn do: T[p]:=p:U[p]:=1:od:for u from 1 to 20 do: k:=1+u:for n from u+1 to nn
do:s:=T[n]+T[u]:s1:=nops(factorset(s)):s2:=bigomega(s):if s1=3 and s2=3 then
U[k]:=T[n]:k:=k+1:else fi:od:for i from 1 to nn do:T[i]:=U[i]:od:od:for j from
1 to 30 do:printf(`%d, `, T[j]):od:
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Lagneau, Jan 31 2011
EXTENSIONS
a(12)-a(17) from Donovan Johnson, Feb 14 2011
STATUS
approved