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 A358408 #11 Nov 16 2022 08:53:36 %S A358408 4,8,32,144,468,1160,2512,4836,8468,13760,21784,31168,46596,64760, %T A358408 86912,114656,154400,194116,253160,310408,382712,469296,580688,677656, %U A358408 822928,969880,1141112,1319984,1566512,1755032,2080376,2349188,2686452,3052184,3450348,3800756,4387404,4880560,5443192 %N A358408 Number of vertices formed in a square by straight line segments when connecting the n-1 points between each corner that divide each edge into n equal parts to the n-1 points on each of the two adjacent edges of the square. %H A358408 Scott R. Shannon, <a href="/A358408/a358408.png">Image for n = 2</a>. %H A358408 Scott R. Shannon, <a href="/A358408/a358408_1.png">Image for n = 3</a>. %H A358408 Scott R. Shannon, <a href="/A358408/a358408_2.png">Image for n = 4</a>. %H A358408 Scott R. Shannon, <a href="/A358408/a358408_3.png">Image for n = 10</a>. %F A358408 a(n) = A358409(n) - A358407(n) + 1 by Euler's formula. %Y A358408 Cf. A358407 (regions), A358409 (edges), A355799, A331449. %K A358408 nonn %O A358408 1,1 %A A358408 _Scott R. Shannon_, Nov 14 2022