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.
%I A380964 #16 Mar 15 2025 17:10:32 %S A380964 9,48,150,494,1202,2542,4635,9738,14943,25917,41196,62518,89657, %T A380964 139743,185114,264483,363291,485411,630099,862106,1067459,1391011, %U A380964 1771817,2210554,2712337,3461467,4115434,5073010,6165577,7387876,8748214,10655591,12333486,14679050,17281206 %N A380964 Perimeter-magic hexagons of order 3 with magic sum n. %C A380964 Each side of the hexagon has 3 integers (=the order), 2 of them shared by adjacent sides. All 12 integers on the vertices must be distinct. Solutions obtained by rotations around the 6-fold axis or flips are considered the same/equivalent (bracelet symmetry). %C A380964 A244879(n-3) counts the perimeter-magic hexagons of order 3 if the 12 integers do not need to be distinct and if solutions by rotations/reflections are considered distinct. - _R. J. Mathar_, Mar 10 2025 %H A380964 Bert Dobbelaere, <a href="/A380964/b380964.txt">Table of n, a(n) for n = 17..100</a> %H A380964 R. J. Mathar, <a href="https://doi.org/10.5281/zenodo.15001365">Generating Perimeter-magic Polygons</a> (C++ source) (2025) %e A380964 For magic sum 17, a(17) = 9. One of the hexagons is 5 9 3 %e A380964 10 8 %e A380964 2 6 %e A380964 14 7 %e A380964 1 12 4 %Y A380964 Cf. A380853 (triangles), A380962 (squares), A380963 (pentagons). %K A380964 nonn %O A380964 17,1 %A A380964 _Derek Holton_ and Alex Holton, Feb 09 2025 %E A380964 More terms from _Bert Dobbelaere_, Mar 15 2025