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 A385258 #7 Jun 26 2025 12:09:17 %S A385258 8,1,5,3,5,7,4,8,3,3,6,2,1,2,6,3,4,0,2,5,2,6,0,2,1,3,1,6,2,6,6,2,7,2, %T A385258 7,0,2,6,7,3,2,1,4,9,0,4,4,9,8,3,7,7,2,2,7,1,4,8,6,3,4,8,6,4,0,9,8,4, %U A385258 8,4,3,6,5,6,8,3,6,7,6,5,2,1,8,9,9,6,8,5,4,9 %N A385258 Decimal expansion of the volume of a gyroelongated square bicupola with unit edge. %C A385258 The gyroelongated square bicupola is Johnson solid J_45. %H A385258 Paolo Xausa, <a href="/A385258/b385258.txt">Table of n, a(n) for n = 1..10000</a> %H A385258 Wikipedia, <a href="https://en.wikipedia.org/wiki/Gyroelongated_square_bicupola">Gyroelongated square bicupola</a>. %F A385258 Equals (2/3)*(3 + 2*sqrt(2) + sqrt(2*(2 + sqrt(2) + sqrt(146 + 103*sqrt(2))))) = (2/3)*(3 + A010466 + sqrt(2*(2 + A002193 + sqrt(146 + 103*A002193)))). %F A385258 Equals the largest real root of 6561*x^8 - 104976*x^7 + 594864*x^6 - 1384128*x^5 - 552096*x^4 + 1569024*x^3 + 246528*x^2 - 119808*x + 4352. %e A385258 8.1535748336212634025260213162662727026732149... %t A385258 First[RealDigits[2/3*(3 + 2*# + Sqrt[2*(2 + # + Sqrt[146 + 103*#])]) & [Sqrt[2]], 10, 100]] (* or *) %t A385258 First[RealDigits[PolyhedronData["J45", "Volume"], 10, 100]] %Y A385258 Cf. A385259 (surface area). %Y A385258 Cf. A002193, A010466, A179587, A384214, A384287, A385256. %K A385258 nonn,cons,easy %O A385258 1,1 %A A385258 _Paolo Xausa_, Jun 26 2025