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A262682 Even bisection of A262680. 4


%S 0,0,2,0,2,0,0,0,2,0,0,0,2,0,0,0,0,0,2,0,0,0,0,0,0,0,0,0,0,0,0,0,2,0,

%T 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,

%U 0,0,0,0,2,0,0,0,2,0,2,0,0,2,0,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,4,2

%N Even bisection of A262680.

%C Number of perfect squares (A000290) encountered before zero is reached when starting from k = 2n and repeatedly applying the map that replaces k by k - d(k), where d(k) is the number of divisors of k (A000005). This count includes n itself if it is a square, but excludes the zero.

%H Antti Karttunen, <a href="/A262682/b262682.txt">Table of n, a(n) for n = 0..10082</a>

%F a(n) = A262680(2*n).

%o (Scheme) (define (A262682 n) (A262680 (+ n n)))

%Y Cf. A000005, A000290, A010052, A049820, A155043, A262677, A262680, A262681.

%K nonn

%O 0,3

%A _Antti Karttunen_, Oct 03 2015

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Last modified July 30 23:12 EDT 2021. Contains 346365 sequences. (Running on oeis4.)