cp's OEIS Frontend

A352975 a(n) is the smallest number which can be represented as the sum of n distinct centered n-gonal numbers in exactly n ways, or -1 if no such number exists.

%I A352975 #42 Feb 16 2025 08:34:03
%S A352975 96,192,330,504,840,1304,1872,2910,3971,5340,6851,8932,11700,14496,
%T A352975 18258,22410,27265,32620,39606,47124,55545,65448,76050,87854,101925,
%U A352975 116956,134125,152340,173538,195424,220473,246942,276570,306756,340918,377644,418821,462720
%N A352975 a(n) is the smallest number which can be represented as the sum of n distinct centered n-gonal numbers in exactly n ways, or -1 if no such number exists.
%C A352975 If a(n) exists, then n divides a(n). - _Thomas Scheuerle_, Apr 13 2022
%H A352975 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CenteredPolygonalNumber.html">Centered Polygonal Number</a>
%F A352975 a(n) >= n*binomial(n + 2, 3) + n, if a(n) exists. - _Thomas Scheuerle_, Apr 13 2022
%e A352975 For n = 3: 96 = 1 + 10 + 85 = 1 + 31 + 64 = 19 + 31 + 46.
%Y A352975 Cf. A101321, A350209, A350397, A350405.
%K A352975 nonn
%O A352975 3,1
%A A352975 _Ilya Gutkovskiy_, Apr 13 2022
%E A352975 a(10)-a(16) from _Thomas Scheuerle_, Apr 13 2022
%E A352975 a(17)-a(40) from _Michael S. Branicky_, May 19 2022