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 A384214 #10 May 24 2025 01:56:29 %S A384214 6,2,1,0,7,6,5,7,9,2,0,3,9,2,0,0,0,3,6,6,5,8,2,2,8,8,3,3,4,5,9,8,0,7, %T A384214 3,1,6,9,6,0,1,0,0,3,2,0,9,1,3,7,4,5,1,7,8,3,6,4,1,8,1,7,0,5,4,3,7,9, %U A384214 9,6,0,4,6,7,0,8,9,3,8,4,9,5,9,9,9,4,2,7,1,3 %N A384214 Decimal expansion of the volume of a gyroelongated square cupola with unit edge. %C A384214 The gyroelongated square cupola is Johnson solid J_23. %H A384214 Paolo Xausa, <a href="/A384214/b384214.txt">Table of n, a(n) for n = 1..10000</a> %H A384214 Wikipedia, <a href="https://en.wikipedia.org/wiki/Gyroelongated_square_cupola">Gyroelongated square cupola</a>. %F A384214 Equals 1 + (2/3)*sqrt(2) + (2/3)*sqrt(4 + 2*sqrt(2) + 2*sqrt(146 + 103*sqrt(2))) = 1 + A010466/3 + (2/3)*sqrt(4 + A010466 + 2*sqrt(146 + 103*A002193)). %F A384214 Equals the largest real root of 6561*x^8 - 52488*x^7 + 113724*x^6 - 9720*x^5 - 1616922*x^4 + 396360*x^3 + 1537020*x^2 - 178632*x - 3391. %e A384214 6.21076579203920003665822883345980731696010032091... %t A384214 First[RealDigits[1 + Sqrt[8]/3 + 2/3*Sqrt[4 + Sqrt[8] + 2*Sqrt[146 + 103*Sqrt[2]]], 10, 100]] (* or *) %t A384214 First[RealDigits[PolyhedronData["J23", "Volume"], 10, 100]] %Y A384214 Cf. A384215 (surface area). %Y A384214 Cf. A002193, A010466, A179587, A179638, A384142. %K A384214 nonn,cons,easy %O A384214 1,1 %A A384214 _Paolo Xausa_, May 23 2025