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 A290876 #5 Aug 13 2017 07:35:41 %S A290876 0,0,1,4,11,25,50,91,153,241,360,525,736,1014,1365,1792,2304,2937, %T A290876 3684,4585,5632,6831,8217,9835,11659,13723,16060,18673,21576,24858, %U A290876 28441,32460,36875,41718,47046,52841,59069,65928,73402,81482,90136 %N A290876 A290865(n) -(n-1). %C A290876 This is the number of regions in the configuration A290447(n) if we remove the baseline. %Y A290876 Cf. A290447, A290865. %K A290876 nonn %O A290876 1,4 %A A290876 _N. J. A. Sloane_, Aug 13 2017