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 A071283 #7 Oct 30 2022 18:19:59 %S A071283 0,0,0,0,1,1,2,1,2,3,2,4,3,1,5,4,6,3,5,7,4,8,6,2,9,7,10,5,8,11,6,12,9, %T A071283 3,13,10,14,7,11,15,8,16,12,4,17,13,18,9,14,19,10,20,15,5,21,16,22,11, %U A071283 17,23,12,24,18,6,25,19,26,13,20,27,14,28,21,7,29,22,30,15,23,31 %N A071283 Numerators of Peirce sequence of order 4. %D A071283 R. L. Graham, D. E. Knuth and O. Patashnik, Concrete Mathematics, Addison-Wesley, Reading, MA, 2nd ed. 1998, p. 151. %F A071283 Conjectures from _Colin Barker_, Mar 29 2017: (Start) %F A071283 G.f.: x^4*(x^19 + x^18 + x^17 + 2*x^16 + 2*x^15 + 3*x^14 + x^13 + 3*x^12 + 4*x^11 + 2*x^10 + 3*x^9 + 2*x^8 + x^7 + 2*x^6 + x^5 + x^4)/(x^20 - 2*x^10 + 1). %F A071283 a(n) = 2*a(n-10) - a(n-20) for n>19. %F A071283 (End) %e A071283 The Peirce sequences of orders 1, 2, 3, 4, 5 begin: %e A071283 0/1 1/1 2/1 3/1 4/1 5/1 6/1 7/1 ... %e A071283 0/2 0/1 1/2 2/2 1/1 3/2 4/2 2/1 ... (numerators are A009947) %e A071283 0/2 0/3 0/1 1/3 1/2 2/3 2/2 3/3 ... %e A071283 0/2 0/4 0/3 0/1 1/4 1/3 2/4 1/2 ... %e A071283 0/2 0/4 0/5 0/3 0/1 1/5 1/4 1/3 ... %Y A071283 Cf. A071281-A071288. %K A071283 nonn,frac,easy %O A071283 0,7 %A A071283 _N. J. A. Sloane_, Jun 11 2002 %E A071283 More terms from _Reiner Martin_, Oct 15 2002