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a(n) = smallest number m, not occurring earlier, such that at least one prime factor of m divides at least one of the omega(m) last terms (where omega=A001221); a(1)=1, a(2)=2.
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%I #8 Sep 19 2012 12:54:53

%S 1,2,4,6,3,9,12,8,10,5,14,7,18,15,20,16,22,11,24,21,26,13,28,30,25,33,

%T 27,36,32,34,17,38,19,40,35,42,39,44,45,46,23,48,50,51,52,54,56,49,58,

%U 29,60,55,57,63,66,62,31,68,64,70,65,72,69,74,37,76,78,75,80,82,41,84

%N a(n) = smallest number m, not occurring earlier, such that at least one prime factor of m divides at least one of the omega(m) last terms (where omega=A001221); a(1)=1, a(2)=2.

%C Max{GCD(a(n),a(n-i)): 1<=i<=A001222(a(n))} > 1, for n>2;

%C integer permutation with inverse A096666: a(A096666(n))=A096666(a(n))=n;

%C a(n) is prime iff a(n-1) = 2*a(n);

%C A096667 = a(a(n)).

%H <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>

%Y Cf. A064413. - _N. J. A. Sloane_, Sep 19 2012

%K nonn

%O 1,2

%A _Reinhard Zumkeller_, Jul 03 2004