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%I #3 Mar 30 2012 17:26:14
%S 1,4,2,6,8,3,5,9,10,7,12,11,13,14,15,17,16,19,18,20,23,21,22,29,31,37,
%T 24,25,41,43,26,27,47,28,53,30,59,32,33,61,34,67,35,71,73,36,38,39,40,
%U 79,83,42,89,44,97,45,101,46,103,107
%N Rearrangement of positive integers according to parity of (prime(n)-1)/2 (see comments).
%C a(1)=1, for n>1: if (prime(n)-1)/2 is even/odd then a(n) is the next prime/composite number.
%t p=Prime[Range[100]];s=Complement[Range[100], p]; bb={1};is=1;ip=0;Do[If[OddQ[(Prime[i]-1)/2], is=is+1;bb=Append[bb, s[[is]]], ip=ip+1;bb=Append[bb, p[[ip]]]], {i, 2, 60}];bb
%Y Cf. A105366.
%K nonn
%O 1,2
%A _Zak Seidov_, Apr 01 2005
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