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%I #9 Jun 16 2022 10:26:43
%S 0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,
%T 0,0,0,0,1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,
%U 0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1
%N a(n) = 1 if n is thrice a prime power congruent to 1 (mod 3), otherwise 0.
%H Antti Karttunen, <a href="/A354983/b354983.txt">Table of n, a(n) for n = 1..100000</a>
%H <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>
%t a[n_] := If[Mod[n, 9] == 3 && PrimePowerQ[n/3], 1, 0]; Array[a, 100] (* _Amiram Eldar_, Jun 15 2022 *)
%o (PARI) A354983(n) = ((3==(n%9)) && isprimepower(n/3));
%Y Characteristic function of A354984.
%Y Cf. A354982.
%K nonn
%O 1
%A _Antti Karttunen_, Jun 15 2022