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a(n) = 1 if 1 + A002322(n) is prime, 0 otherwise, where A002322 is Carmichael lambda.
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%I #15 Sep 23 2020 12:51:59

%S 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,

%T 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,1,1,1,

%U 1,1,1,1,1,1,0,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,0,1,1,1,1,1,1,1,1,1,0,1,1,1,1,0,1,1,1,0,1

%N a(n) = 1 if 1 + A002322(n) is prime, 0 otherwise, where A002322 is Carmichael lambda.

%C Out of the first 65537 values, 39743 are 1's (indicating primes), and 25794 are 0's, indicating nonprimes.

%H Antti Karttunen, <a href="/A296077/b296077.txt">Table of n, a(n) for n = 1..65537</a>

%H <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>

%F a(n) = A010051(A263027(n)) = A010051(1+A002322(n)).

%t Table[If[PrimeQ[CarmichaelLambda[n]+1],1,0],{n,120}] (* _Harvey P. Dale_, Sep 23 2020 *)

%o (PARI) A296077(n) = isprime(1+lcm(znstar(n)[2]));

%Y Characteristic function for A263028.

%Y Cf. A002322, A010051, A263027, A263029 (positions of zeros), A296076, A296079.

%K nonn

%O 1,1

%A _Antti Karttunen_, Dec 05 2017