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A354031
a(n) = 1 if n > 1 and n is a power of a Pythagorean prime (prime of the form 4m+1), otherwise 0.
3
0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 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, 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, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 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
OFFSET
1
FORMULA
a(n) = [A024362(n) == 1], where [ ] is the Iverson bracket.
a(n) = A174275(n) - A354033(n).
a(n) <= A354030(n).
PROG
(PARI) A354031(n) = { my(p=0); (isprimepower(n, &p) && (1==(p%4))); };
CROSSREFS
Characteristic function of A120960, Pythagorean prime powers.
Sequence in context: A079260 A358678 A359150 * A354035 A025457 A350289
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 15 2022
STATUS
approved