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.

A374193 a(n) is the smallest number which can be represented as the sum of two nonzero pentagonal pyramidal numbers in exactly n ways, or -1 if no such number exists.

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%I A374193 #15 Feb 16 2025 08:34:07
%S A374193 2,1471,269406
%N A374193 a(n) is the smallest number which can be represented as the sum of two nonzero pentagonal pyramidal numbers in exactly n ways, or -1 if no such number exists.
%C A374193 There are no further positive terms <= 10^15. - _Michael S. Branicky_, Jul 01 2024
%H A374193 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PentagonalPyramidalNumber.html">Pentagonal Pyramidal Number</a>
%e A374193 a(2) = 1471 = 1 + 1470 = 288 + 1183.
%Y A374193 Cf. A002411, A011541, A332989, A334013, A374168, A374194.
%K A374193 nonn,hard,more,bref
%O A374193 1,1
%A A374193 _Ilya Gutkovskiy_, Jun 30 2024