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 A303817 #37 Dec 22 2019 19:12:42 %S A303817 2,1,1,7,6,4,7,0,5,8,8,2,3,5,2,9,4,1,1,7,6,4,7,0,5,8,8,2,3,5,2,9,4,1, %T A303817 1,7,6,4,7,0,5,8,8,2,3,5,2,9,4,1,1,7,6,4,7,0,5,8,8,2,3,5,2,9,4,1,1,7, %U A303817 6,4,7,0,5,8,8,2,3,5,2,9,4,1,1,7,6,4,7,0,5,8,8,2,3,5,2,9,4,1,1,7,6,4,7,0,5 %N A303817 Decimal expansion of 360/17. %C A303817 Decimal expansion of the external angle of the regular heptadecagon (in degrees). %C A303817 The repeating pattern [1, 7, 6, 4, 7, 0, 5, 8, 8, 2, 3, 5, 2, 9, 4, 1] is the same as A007450. - _Michael B. Porter_, Jun 11 2018 %C A303817 Period 16. - _Eric Chen_, Jun 14 2018 %C A303817 Essentially the same as A021089. - _R. J. Mathar_, Aug 16 2018 %H A303817 Wikipedia, <a href="https://en.wikipedia.org/wiki/Heptadecagon">Heptadecagon</a> %F A303817 Equals 21 + (3/17) = 180 - A303816. %F A303817 From _Chai Wah Wu_, Dec 20 2019: (Start) %F A303817 a(n) = a(n-1) - a(n-8) + a(n-9) for n > 11. %F A303817 G.f.: x^2*(-2*x^9 - 7*x^8 + 7*x^7 - 3*x^6 + 2*x^5 + x^4 - 6*x^3 + x - 2)/((x - 1)*(x^8 + 1)). (End) %e A303817 21.176470588235294117647058823529411764705882352941176470588235294... %t A303817 RealDigits[360/17, 10, 111][[1]] (* _Robert G. Wilson v_, Jun 13 2018 *) %Y A303817 Cf. A007450, A019434, A210644, A210649, A303816. %K A303817 nonn,cons,easy %O A303817 2,1 %A A303817 _Omar E. Pol_, Apr 30 2018