"Double and Reverse" chains of primes
{389047, 490877, 457189, 873419, 8386471, 24927761}
{3632297, 4954627, 4529099, 8918509, 81073871, 247741261}
{3733637, 4727647, 4925549, 8901589, 87130871, 247162471}
{3957097, 4914197, 4938289, 8756789, 87531571, 241360571}
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Zak Seidov