# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a358407 Showing 1-1 of 1 %I A358407 #15 Nov 16 2022 08:53:43 %S A358407 1,5,37,173,553,1365,2909,5513,9577,15485,24157,35021,51201,71013, %T A358407 95621,126277,167213,211737,272025,335681,413677,505445,618557,729485, %U A358407 878017,1034697,1215185,1409273,1654785,1875265,2192281,2486797,2836317,3216833,3633709,4034313,4599789,5124841 %N A358407 Number of regions 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 A358407 Scott R. Shannon, Image for n = 2. %H A358407 Scott R. Shannon, Image for n = 3. %H A358407 Scott R. Shannon, Image for n = 4. %H A358407 Scott R. Shannon, Image for n = 10. %H A358407 Scott R. Shannon, Image for n = 20. %F A358407 a(n) = A358409(n) - A358408(n) + 1 by Euler's formula. %Y A358407 Cf. A358408 (vertices), A358409 (edges), A355798, A255011. %K A358407 nonn %O A358407 1,2 %A A358407 _Scott R. Shannon_, Nov 14 2022 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE