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A373979
a(n) = 1 if n is a nonprime of the form 4*k + 3, otherwise 0.
2
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0
OFFSET
1
MATHEMATICA
a[n_]:=Boole[!PrimeQ[n]&&Mod[n, 4]==3]; Array[a, 125](* Stefano Spezia, Jun 25 2024 *)
PROG
(PARI) A373979(n) = (!isprime(n) && 3==(n%4));
CROSSREFS
Characteristic function of A091236.
Cf. also A079261, A373978.
Sequence in context: A360111 A359162 A327932 * A359546 A354989 A277161
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jun 25 2024
STATUS
approved