A102609 - OEIS

%I #8 Feb 16 2025 08:32:56

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

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

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

%N a(n) = 1 iff n^2-n+41 is prime (else 0).

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Prime-GeneratingPolynomial.html">Prime-Generating Polynomial</a>.

%e a(39) = 1 because 39^2 - 39 + 41 = 1523 is prime.

%t Table[If[PrimeQ[n^2 - n + 41], 1, 0], {n, 1, 150}]

%o (PARI) a(n) = isprime(n^2-n+41); \\ _Michel Marcus_, Mar 08 2023

%Y Cf. A005846, A202018.

%K nonn

%O 0

%A Joseph Biberstine (jrbibers(AT)indiana.edu), Jan 29 2005

%E a(0) = 1 prepended by _Michel Marcus_, Mar 08 2023