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 A247446 #17 Mar 24 2021 09:14:41 %S A247446 3,4,0,0,8,7,3,8,0,7,9,3,9,1,5,8,4,6,9,8,6,3,8,9,6,7,3,3,0,7,9,0,4,1, %T A247446 9,9,8,0,3,2,6,2,4,2,1,5,1,7,3,8,8,8,5,7,9,1,9,3,5,3,4,2,5,3,8,5,2,7, %U A247446 3,0,9,6,4,6,1,1,9,1,3,5,3,1,9,0,7,7,3,4,3,5,2,8,9,7,6,1,2,8,1,6,6,0,5,4,1,7 %N A247446 Decimal expansion of Pi*sqrt(3)/16. %C A247446 The atomic packing factor (APF) of the diamond cubic crystal lattice and the smallest APF among all crystallographic lattices filled by spheres of the same diameter. The APF of the body-centered-cubic (bcc) lattice packed with spheres of the same diameter is twice this value (see Examples). For other crystal lattices, see the cross-refs. %H A247446 Stanislav Sykora, <a href="/A247446/b247446.txt">Table of n, a(n) for n = 0..2000</a> %H A247446 Steve Sque, <a href="https://www.stevesque.com/diamond/structure/">Structure of Diamond</a> (adapted from 2005 thesis) %H A247446 Wikipedia, <a href="https://en.wikipedia.org/wiki/Diamond_cubic">Diamond cubic</a> %H A247446 Wikipedia, <a href="https://en.wikipedia.org/wiki/Atomic_packing_factor">Atomic packing factor</a> %H A247446 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a> %e A247446 0.340087380793915846986389673307904199803262421517388857919353425385273... %e A247446 APF of the bcc lattice packed with spheres of the same diameter: %e A247446 0.680174761587831693972779346615808399606524843034777715838706850770546... %t A247446 RealDigits[Pi*Sqrt[3]/16,10,120][[1]] (* _Vaclav Kotesovec_, Oct 04 2014 *) %o A247446 (PARI) Pi*sqrt(3)/16 %Y A247446 Cf. APF's of other crystal lattices: A093825 (hcp,fcc), A019673 (simple cubic). %K A247446 nonn,cons,easy %O A247446 0,1 %A A247446 _Stanislav Sykora_, Sep 29 2014