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%I #12 Apr 27 2023 11:23:16
%S 1,3,5,6,9,10,14,15,20,21
%N Numbers of unit circles packed in a triangle of smallest area admitting an equilateral triangle solution.
%H Erich Friedman, <a href="https://erich-friedman.github.io/packing/cirinttt/">Circles in Arbitrary Triangles</a>
%Y May be related to A117142.
%Y For packing into equilateral triangles, see A337019.
%K nonn,hard,more
%O 1,2
%A _Leonid Broukhis_, Feb 19 2016