%I A126196
%S A126196 7,546,1092,1755,3510,4896,52447
%N A126196 Numbers n such that gcd(numerator(H(n)),numerator(H([n/2]))) > 1, where 
               H() are the harmonic numbers.
%C A126196 Note a connection to the Wieferich primes A001220(n) = {1093, 3511} = 
               primes p such that p^2 divides 2^(p-1) - 1. a(3) = 1093 - 1. a(4) 
               = (3511- 1)/2. a(5) = 3511 - 1.
%Y A126196 Cf. A126197, A001008 and A125581.
%Y A126196 Cf. A125581 = numbers n such that n does not divide the denominator of 
               the n-th harmonic number nor the denominator of the n-th alternating 
               harmonic number. Cf. A126197 = GCD's arising in A126196. Cf. A001220 
               = Wieferich primes p: p^2 divides 2^(p-1) - 1. Cf. A001008, A002805 
               = Denominator of the n-th harmonic number. Cf. A058313, A058312 = 
               Denominator of the n-th alternating harmonic number. Cf. A074791 
               = numbers n such that n does not divide the denominator of the n-th 
               harmonic number. Cf. A121594 = numbers n such that n does not divide 
               the denominator of the n-th alternating harmonic number.
%Y A126196 Sequence in context: A003396 A124899 A056852 this_sequence A093169 A159029 
               A068616
%Y A126196 Adjacent sequences: A126193 A126194 A126195 this_sequence A126197 A126198 
               A126199
%K A126196 nonn
%O A126196 1,1
%A A126196 Max Alekseyev and Tanya Khovanova, Mar 07 2007, corrected Mar 10 2007