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 A071287 #8 Oct 30 2022 18:19:59 %S A071287 0,0,0,0,0,0,1,1,1,2,1,2,2,3,1,3,4,2,3,4,5,2,4,6,5,3,1,7,6,5,8,4,7,6, %T A071287 9,3,8,10,5,7,9,11,4,8,12,10,6,2,13,11,9,14,7,12,10,15,5,13,16,8,11, %U A071287 14,17,6,12,18,15,9,3,19,16,13,20,10,17,14,21,7,18,22 %N A071287 Numerators of Peirce sequence of order 6. %D A071287 R. L. Graham, D. E. Knuth and O. Patashnik, Concrete Mathematics, Addison-Wesley, Reading, MA, 2nd ed. 1998, p. 151. %F A071287 Conjectures from _Colin Barker_, Mar 29 2017: (Start) %F A071287 G.f.: x^6*(x^41 + x^40 + x^39 + x^38 + 2*x^37 + 2*x^36 + x^35 + 3*x^34 + 2*x^33 + 3*x^32 + 2*x^31 + 4*x^30 + 3*x^29 + 4*x^28 + 5*x^27 + x^26 + 3*x^25 + 5*x^24 + 6*x^23 + 4*x^22 + 2*x^21 + 5*x^20 + 4*x^19 + 3*x^18 + 2*x^17 + 4*x^16 + 3*x^15 + x^14 + 3*x^13 + 2*x^12 + 2*x^11 + x^10 + 2*x^9 + x^8 + x^7 + x^6)/(x^42 - 2*x^21 + 1). %F A071287 a(n) = 2*a(n-21) - a(n-42) for n>41. %F A071287 (End) %e A071287 The Peirce sequences of orders 1, 2, 3, 4, 5 begin: %e A071287 0/1 1/1 2/1 3/1 4/1 5/1 6/1 7/1 ... %e A071287 0/2 0/1 1/2 2/2 1/1 3/2 4/2 2/1 ... (numerators are A009947) %e A071287 0/2 0/3 0/1 1/3 1/2 2/3 2/2 3/3 ... %e A071287 0/2 0/4 0/3 0/1 1/4 1/3 2/4 1/2 ... %e A071287 0/2 0/4 0/5 0/3 0/1 1/5 1/4 1/3 ... %Y A071287 Cf. A071281-A071288. %K A071287 nonn,frac,easy %O A071287 0,10 %A A071287 _N. J. A. Sloane_, Jun 11 2002 %E A071287 More terms from _Reiner Martin_, Oct 15 2002