GCD(phi(a(n)),a(n)-1) = number of divisors of (a(n)-1).
2, 3, 105, 133, 153, 185, 345, 377, 425, 585, 637, 665, 777, 805, 825, 873, 897, 905
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Fri Dec 26 23:06:26 CET 2008 [seqfan] Some items inspired by appearances of 2009 in the OEIS