%I A106840
%S A106840 1,4,8,9,16,17,20,25,32,33,36,40,41,49,52,57,64,65,68,72,73,80,81,84,89,
%T A106840 97,100,104,105,113,116,121,128,129,132,136,137,144,145,148,153,160,161,
%U A106840 164,168,169,177,180,185,193,196,200,201,208,209,212,217,225
%N A106840 Numbers n such that both n and n+1 have odd part of form 4k+1.
%e A106840 20/4=5 is 1 mod 4 and so is 21, therefore 20 is in sequence.
%Y A106840 Cf. A091072, A106841, A106837.
%Y A106840 Contains A106841 and A106841+1.
%Y A106840 Sequence in context: A072103 A004756 A153034 this_sequence A140612 A160053 
               A034023
%Y A106840 Adjacent sequences: A106837 A106838 A106839 this_sequence A106841 A106842 
               A106843
%K A106840 nonn
%O A106840 1,2
%A A106840 Ralf Stephan, May 03 2005