OFFSET
0,2
COMMENTS
MAPLE
isA016921 := proc(n)
(n mod 6)=1 ;
end proc:
isA091300 := proc(n)
(not isprime(n)) and isA016921(n) ;
end proc:
isA199859 := proc(n)
if n = 1 then
return true;
elif isA091300(6*n-5) then
for d in numtheory[divisors](6*n-5) minus {1, 6*n-5} do
if isA016921(d) and isA016921((6*n-5)/d) then
return true;
end if;
end do:
return false;
else
return false;
end if;
end proc:
for n from 1 to 210 do
if isA199859(n) then
printf("%d, ", n) ;
end if ;
end do; # R. J. Mathar, Nov 25 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Eleonora Echeverri-Toro, Nov 11 2011
STATUS
approved