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%I #3 Mar 30 2012 18:50:43
%S 6,15,28,40,91,153,190,220,325,496,544,561,572,627,703,861,897,935,
%T 946,1012,1225,1287,1292,1431,1581,1610,1653,1768,1891,2278,2300,2465,
%U 2618,2701,2967,3321,3344,3496,3596,3655,3952,4123,4301,4324,4371
%N Numbers having exactly one divisor d such that for some x also d-x and d+x are divisors.
%C A091009(a(n)) = 1.
%Y Cf. A091013, A091011.
%K nonn
%O 1,1
%A _Reinhard Zumkeller_, Dec 13 2003