cp's OEIS Frontend

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.

A380775 Decimal expansion of the long/short edge length ratio of a pentagonal icositetrahedron.

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%I A380775 #7 Feb 03 2025 14:12:07
%S A380775 1,4,1,9,6,4,3,3,7,7,6,0,7,0,8,0,5,6,6,2,7,5,9,2,6,2,8,2,3,2,6,6,4,3,
%T A380775 3,0,0,2,1,2,0,8,9,3,7,3,0,4,8,7,9,6,1,2,3,3,8,9,3,7,9,3,1,9,7,0,2,1,
%U A380775 0,1,6,1,1,0,4,0,9,8,3,2,1,2,8,6,9,2,1,7,7,0
%N A380775 Decimal expansion of the long/short edge length ratio of a pentagonal icositetrahedron.
%H A380775 Paolo Xausa, <a href="/A380775/b380775.txt">Table of n, a(n) for n = 1..10000</a>
%H A380775 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PentagonalIcositetrahedron.html">Pentagonal Icositetrahedron</a>.
%H A380775 Wikipedia, <a href="https://en.wikipedia.org/wiki/Pentagonal_icositetrahedron">Pentagonal icositetrahedron</a>.
%F A380775 Equals (A058265 + 1)/2.
%F A380775 Equals the real root of 4*x^3 - 8*x^2 + 4*x - 1.
%e A380775 1.419643377607080566275926282326643300212089373...
%t A380775 First[RealDigits[Root[4*#^3 - 8*#^2 + 4*# - 1 &, 1], 10, 100]]
%Y A380775 Cf. A058265, A378823, A378824, A378825, A378826, A378827, A380776, A380777.
%K A380775 nonn,cons,easy
%O A380775 1,2
%A A380775 _Paolo Xausa_, Feb 02 2025