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A349906 Number of factorizations of n into even factors > 1 (a(1) = 1 by convention). 3

%I

%S 1,1,0,2,0,1,0,3,0,1,0,2,0,1,0,5,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,7,0,1,

%T 0,3,0,1,0,4,0,1,0,2,0,1,0,7,0,1,0,2,0,1,0,4,0,1,0,3,0,1,0,11,0,1,0,2,

%U 0,1,0,6,0,1,0,2,0,1,0,7,0,1,0,3,0,1,0,4,0,1,0,2,0,1,0,12,0,1,0,3,0,1,0,4,0

%N Number of factorizations of n into even factors > 1 (a(1) = 1 by convention).

%H Antti Karttunen, <a href="/A349906/b349906.txt">Table of n, a(n) for n = 1..20000</a>

%o (PARI) A349906(n, m=n) = if(1==n, 1, my(s=0); fordiv(n, d, if((d>1)&&(d<=m)&&!(d%2), s += A349906(n/d, d))); (s));

%Y Cf. A001055, A340785 (even bisection), A349907.

%K nonn

%O 1,4

%A _Antti Karttunen_, Dec 13 2021

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Last modified September 25 09:46 EDT 2022. Contains 356977 sequences. (Running on oeis4.)