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 A195399 #12 Nov 26 2024 16:30:03 %S A195399 1,7,5,9,3,8,2,1,5,7,0,9,6,4,9,2,5,5,8,8,6,5,1,6,3,5,2,4,9,0,0,3,8,2, %T A195399 0,7,0,9,2,3,3,3,8,0,9,1,3,8,8,5,4,5,5,9,0,2,6,6,5,7,5,0,5,6,7,4,7,1, %U A195399 6,9,1,9,7,9,7,9,3,7,4,3,5,5,4,2,1,6,8,6,5,2,7,1,7,1,1,7,4,6,9,6 %N A195399 Decimal expansion of shortest length, (A), of segment from side AB through incenter to side AC in right triangle ABC with sidelengths (a,b,c)=(sqrt(7),3,4). %C A195399 See A195284 for definitions and a general discussion. %H A195399 <a href="/index/Al#algebraic_04">Index entries for algebraic numbers, degree 4</a> %e A195399 (A)=1.75938215709649255886516352490038207092333... %t A195399 a = Sqrt[7]; b = 3; c = 4; %t A195399 f = 2 a*b/(a + b + c); %t A195399 x1 = Simplify[f*Sqrt[a^2 + (b + c)^2]/(b + c) ] %t A195399 x2 = Simplify[f*Sqrt[b^2 + (c + a)^2]/(c + a) ] %t A195399 x3 = f*Sqrt[2] %t A195399 N[x1, 100] %t A195399 RealDigits[%] (* (A) A195399 *) %t A195399 N[x2, 100] %t A195399 RealDigits[%] (* (B) A195400 *) %t A195399 N[x3, 100] %t A195399 RealDigits[%] (* (C) A195401 *) %t A195399 N[(x1 + x2 + x3)/(a + b + c), 100] %t A195399 RealDigits[%] (* Philo(ABC,I) A195402 *) %o A195399 (PARI) sqrt(8)*(7-sqrt(7))/7 \\ _Charles R Greathouse IV_, Nov 26 2024 %o A195399 (PARI) polrootsreal(49*x^4-896*x^2+2304)[3] \\ _Charles R Greathouse IV_, Nov 26 2024 %Y A195399 Cf. A195284, A195400, A195401, A195402. %K A195399 nonn,cons %O A195399 1,2 %A A195399 _Clark Kimberling_, Sep 17 2011