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 A097715 #18 Jul 01 2025 08:29:26 %S A097715 6,0,6,2,1,7,7,8,2,6,4,9,1,0,7,0,5,2,7,3,4,6,0,6,2,1,9,5,2,7,0,5,5,3, %T A097715 2,8,4,2,9,9,8,1,8,3,8,8,3,3,6,3,3,2,1,9,8,1,9,5,3,2,4,4,2,8,0,8,1,7, %U A097715 6,5,5,5,9,1,8,0,8,0,0,1,2,9,7,8,4,0,1,1,6,5,3,6,5,0,3,7,0,0,1,4,8,6,4,6,9 %N A097715 Decimal expansion of 7*sqrt(3)/2. %C A097715 Corresponds to the minimal height-to-diameter ratio of a cylinder such that seven of them may be placed in mutual contact. %C A097715 Also the surface area of a triaugmented triangular prism (Johnson solid J_51) with unit edge. - _Paolo Xausa_, Jul 01 2025 %D A097715 Martin Gardner, The Scientific American book of Mathematical Puzzles & Diversions, pp. 115 Simon & Shuster NY 1959 (or Hexaflexagons And Other Mathematical Diversions, The Univ. of Chicago Press Chicago IL 1988). %H A097715 Paolo Xausa, <a href="/A097715/b097715.txt">Table of n, a(n) for n = 1..10000</a> %H A097715 Wikipedia, <a href="https://en.wikipedia.org/wiki/Triaugmented_triangular_prism">Triaugmented triangular prism</a>. %e A097715 6.0621778264910705273460621952705532842998183883363... %t A097715 RealDigits[7Sqrt[3]/2, 10, 105][[1]] %Y A097715 Cf. A002194, A385506. %K A097715 nonn,easy,cons %O A097715 1,1 %A A097715 _Lekraj Beedassy_, Sep 21 2004 %E A097715 Corrected and extended by _Rick L. Shepherd_ and _Ray Chandler_, Sep 21 2004