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%I #8 Sep 08 2022 08:46:13
%S 1,3,5,1,11,1,17,1,1,1,31,1,41,1,1,1,59,1,67,1,1,1,83,1,1,1,1,1,109,1,
%T 127,1,1,1,1,1,157,1,1,1,179,1,191,1,1,1,211,1,1,1,1,1,241,1,1,1,1,1,
%U 277,1,283,1,1,1,1,1,331,1,1,1,353,1,367,1,1,1,1
%N a(n) = prime(n) if n prime otherwise 1.
%C The subsequence of prime terms is A006450.
%e a(7) = 17 because prime(7) = 17 is prime.
%e a(8) = 1 because 8 is not prime.
%t Table[If[! PrimeQ[n], 1, Prime[n]], {n, 100}]
%o (Magma) [IsPrime(n) select NthPrime(n) else 1: n in [1..100]];
%Y Cf. A006450, A007821, A010051, A061397, A191558, A259175.
%K nonn,easy
%O 1,2
%A _Vincenzo Librandi_, Jun 20 2015