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Twice A032741.
2

%I #5 Sep 20 2018 00:33:32

%S 0,0,2,2,4,2,6,2,6,4,6,2,10,2,6,6,8,2,10,2,10,6,6,2,14,4,6,6,10,2,14,

%T 2,10,6,6,6,16,2,6,6,14,2,14,2,10,10,6,2,18,4,10,6,10,2,14,6,14,6,6,2,

%U 22,2,6,10,12,6,14,2,10,6,14,2,22,2,6,10,10,6,14,2,18,8,6,2,22,6,6,6,14,2,22,6,10,6,6,6,22,2,10,10,16

%N Twice A032741.

%C For n>0, twice the number of proper divisors of n (d|n, d<n).

%H Claude Lenormand, <a href="/A318921/a318921.pdf">Deux transformations sur les mots</a>, Preprint, 5 pages, Nov 17 2003. Apparently unpublished. This is a scanned copy of the version that the author sent to me in 2003.

%Y Cf. A032741.

%Y A column of the triangle in A319411.

%K nonn

%O 0,3

%A _N. J. A. Sloane_, Sep 20 2018