divisors

divisorslenstra(245784, 1, 65)
divisorslenstra(245784, 19, 65)
divisorslenstra(288288, 1, 71)
divisorslenstra(288288, 28, 71)
divisorslenstra(2841696, 2, 175)
divisorslenstra(2841696, 23, 175)
divisorslenstra(1680,1,13)
divisorslenstra(4,1,2) \\ #1930
divisorslenstra(2,1,2)

divisors(1)
divisors(12)
divisors(1, 1)
divisors(12, 1)
{
for (i=1,100,
  d = divisors(i,1);
  for(j=1,#d, if (factorback(d[j][2])!=d[j][1],error(i))));
}

fordivfactored(100, d, print(d))