cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A363253 a(n) is the smallest n-gonal number which can be represented as the sum of distinct nonzero n-gonal numbers in exactly n ways, or -1 if no such number exists.

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%I A363253 #8 Feb 16 2025 08:34:05
%S A363253 28,121,210
%N A363253 a(n) is the smallest n-gonal number which can be represented as the sum of distinct nonzero n-gonal numbers in exactly n ways, or -1 if no such number exists.
%C A363253 a(8) = 736, a(9) = 969.
%H A363253 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PolygonalNumber.html">Polygonal Number</a>
%e A363253 For n = 3: 1 + 6 + 21 = 3 + 10 + 15 = 28.
%Y A363253 Cf. A057145, A350207, A350405, A350423.
%K A363253 nonn,bref,more,hard
%O A363253 3,1
%A A363253 _Ilya Gutkovskiy_, May 23 2023