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%I #5 Dec 27 2023 09:03:06
%S 15,144,10045,21945,220077,99008
%N a(n) is the least n-gonal number that can be expressed as the difference of two positive n-gonal numbers in exactly n ways.
%C The corresponding indices of n-gonal numbers are in A368074.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PolygonalNumber.html">Polygonal Number</a>
%e a(3) = 15: 15 = 21 - 6 = 36 - 21 = 120 - 105.
%Y Cf. A086270, A338105, A368041, A368074.
%K nonn,more
%O 3,1
%A _Ilya Gutkovskiy_, Dec 10 2023
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