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%I #29 Jul 07 2022 02:27:00
%S 39,36,30,21,21,15,27,675
%N a(n) = smallest magic sum of any 3 X 3 magic square which contains exactly n numbers that are triangular or square.
%C a(8) and a(9) are greater than 10^10. - _Arkadiusz Wesolowski_, Oct 27 2018
%C a(8) <= 3*7215727335550^2 = (A221669(1) + A221669(2) + A221669(3))*16978181966^2. - _Arkadiusz Wesolowski_, May 21 2022
%H Andrew Bremner, <a href="http://www.multimagie.com/Bremner2.pdf">On squares of squares II</a>, Acta Arithmetica 99 (2001), pp. 289-308.
%H Multimagic Squares, <a href="http://www.multimagie.com/">Home Page</a>
%H The Prime Puzzles and Problems Connection, <a href="http://www.primepuzzles.net/problems/prob_063.htm">Problem 63</a>
%H Arkadiusz Wesolowski, <a href="/A268856/a268856.txt">Examples of these magic squares</a>
%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Magic_square">Magic square</a>
%H <a href="/index/Mag#magic">Index entries for sequences related to magic squares</a>
%Y Cf. A268854, A268855, A269231.
%K nonn,fini,hard,more
%O 0,1
%A _Arkadiusz Wesolowski_, Feb 14 2016
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