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 A385534 #8 Jul 03 2025 10:05:42 %S A385534 2,1,9,1,8,8,1,9,2,1,3,7,9,9,9,8,6,0,5,6,9,2,9,0,8,2,1,8,7,9,1,8,4,2, %T A385534 2,9,2,2,6,3,9,3,1,4,6,1,8,0,2,5,1,4,3,5,3,5,9,9,3,2,1,2,8,6,3,5,4,1, %U A385534 1,3,1,5,1,6,9,6,3,3,5,2,4,4,2,8,2,5,7,0,4,1 %N A385534 Decimal expansion of the volume of a biaugmented pentagonal prism with unit edge. %C A385534 The biaugmented pentagonal prism is Johnson solid J_53. %H A385534 Paolo Xausa, <a href="/A385534/b385534.txt">Table of n, a(n) for n = 1..10000</a> %H A385534 Wikipedia, <a href="https://en.wikipedia.org/wiki/Biaugmented_pentagonal_prism">Biaugmented pentagonal prism</a>. %F A385534 Equals sqrt(257 + 90*sqrt(5) + 24*sqrt(50 + 20*sqrt(5)))/12 = sqrt(257 + 90*A002163 + 24*sqrt(50 + 20*A002163))/12. %F A385534 Equals the largest root of 429981696*x^8 - 3069591552*x^6 + 5343542784*x^4 - 2504731968*x^2 + 10569001. %e A385534 2.1918819213799986056929082187918422922639314618025... %t A385534 First[RealDigits[Sqrt[257 + 90*Sqrt[5] + 24*Sqrt[50 + 20*Sqrt[5]]]/12, 10, 100]] (* or *) %t A385534 First[RealDigits[PolyhedronData["J53", "Volume"], 10, 100]] %Y A385534 Cf. A385535 (surface area). %Y A385534 Cf. A002163, A385509. %K A385534 nonn,cons,easy %O A385534 1,1 %A A385534 _Paolo Xausa_, Jul 03 2025