%I #13 Jul 11 2022 02:39:02
%S 1,2,3,1,5,2,7,3,1,5,11,2,13,7,3,1,17,5,19,11,2,13,23,7,3,1,17,5,29,
%T 19,31,11,2,13,23,7,37,3,1,17,41,5,43,29,19,31,47,11,2,13,23,7,53,37,
%U 3,1,17,41,59,5,61,43,29,19,31,47,67,11,2,13,71,23,73
%N If n is the k-th composite number then a(n) = a(k), otherwise a(n) = n.
%H Rémy Sigrist, <a href="/A328661/b328661.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) = 1 iff n belongs to A006508.
%e a(42) = a(28) = a(18) = a(10) = a(5) = 5.
%o (PARI) k=0; for (n=1, #a=vector(73), print1 (a[n] = if (bigomega(n)>1, a[k++], n) ", "))
%Y See A288469 and A328018 for similar sequences.
%Y Cf. A002808, A006508.
%K nonn
%O 1,2
%A _Rémy Sigrist_, Oct 24 2019