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 A359047 #15 Dec 15 2022 06:47:51 %S A359047 1,4,12,84,120,330,504,1240,1332,2850,3696,5172,7176,10906,12660, %T A359047 19280,22440,28494,35796,46220,52752,68662,79488,91272,111000,136838, %U A359047 149472,181972,204972,229650,268212,317024,343860,404090,441420,496764,553224,636538,679224,776200,839844,914634,1017036 %N A359047 Number of distinct edges among all circles that can be constructed on vertices of an n-sided regular polygon, using only a compass. %C A359047 See A331702 and A359046 for further details and images. %C A359047 No formula for a(n) is currently known. %F A359047 a(n) = A331702(n) + A359046(n) - 1 by Euler's formula. %Y A359047 Cf. A331702 (vertices), A359046 (regions), A359061 (k-gons), A358783, A135565. %K A359047 nonn %O A359047 1,2 %A A359047 _Scott R. Shannon_, Dec 14 2022