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 A057672 #8 Jul 02 2025 16:02:00 %S A057672 0,0,1,3,5,7,10,13,17,21,25,30,36,42,48,54,62,69,77,85,94,103,113,123, %T A057672 134,145,156,168,180,193,206,219,233,248,262,278,293,309,326,343,360, %U A057672 378,396,415,434,454,474,494,515,536,558,580,602,625,649,672,697,721,747,772,798 %N A057672 a(n) equals floor(As(n) - Ac(n)), where As(n) is the area of the square with side length n and Ac(n) is the area of the circle of diameter n. %F A057672 a(n) = floor(n^2*(1-Pi/4)). %e A057672 a(7)=10 since floor(7^2(1-Pi/4)) = 10. %o A057672 (PARI) a(n)=floor(n^2*(1-Pi/4)); \\ _Michel Marcus_, Sep 05 2014 %Y A057672 Cf. A057671. %K A057672 nonn %O A057672 1,4 %A A057672 seiringer.flor(AT)eudoramail.com, Oct 18 2000 %E A057672 Edited and extended by _James Sellers_, Oct 20 2000