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%I #15 Jun 03 2024 18:32:01
%S 0,1,0,2,1,2,0,1,2,5,4,5,3,4,3,1,2,3,0,1,0,2,1,2,0,1,0,4,3,4,2,1,2,0,
%T 1,2,5,4,3,5,6,7,5,6,5,2,3,4,6,5,4,6,5,6,2,1,2,0,1,2,0,1,0,3,4,5,3,4,
%U 3,5,4,5,2,3,2,0,1,0,2,3,4,9,8,9,7,8,7
%N a(n) = 3-adic valuation of A008336(3*n).
%H Michael De Vlieger, <a href="/A372095/b372095.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) = A007949(A008336(3*n)).
%t k = 2; nn = 360; p[_] := 0; r = 0; q = Prime[k];
%t {0}~Join~Reap[
%t Do[If[AnyTrue[#, p[#1] < #2 & @@ # &],
%t Map[p[#1] += #2 & @@ # &, #],
%t Map[p[#1] -= #2 & @@ # &, #] ] &@
%t Map[{PrimePi[#1], #2} & @@ # &, FactorInteger[n]];
%t If[Divisible[n, q], Sow[p[k] ] ], {n, nn}] ][[-1, 1]]
%Y Cf. A007949, A008336, A371908, A372840.
%K nonn,easy
%O 1,4
%A _Michael De Vlieger_, Jun 02 2024