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A353800
a(n) = 1 if n is a power of prime with an even exponent, otherwise 0.
2
1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 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, 0, 0, 0, 1, 0, 0, 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, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
OFFSET
1
FORMULA
a(n) = A010055(n) - A353817(n).
a(n) >= A302048(n).
EXAMPLE
a(1) = 1 because 1 = p^0 for any prime p, and 0 is an even number.
MATHEMATICA
a[n_] := If[n == 1 || (Length[(f = FactorInteger[n])] == 1 && EvenQ[f[[1, 2]]]), 1, 0]; Array[a, 100] (* Amiram Eldar, May 15 2022 *)
PROG
(PARI) A353800(n) = ((1==n)||((n=isprimepower(n))&&!(n%2)));
CROSSREFS
Characteristic function of A056798.
Sequence in context: A014999 A227291 A271102 * A353374 A326072 A304362
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 15 2022
STATUS
approved