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 A292350 #16 Dec 09 2017 14:25:50 %S A292350 0,9,116,670,2580,7735,19544,43596,88440,166485,295020,497354,804076, %T A292350 1254435,1897840,2795480,4022064,5667681,7839780,10665270,14292740, %U A292350 18894799,24670536,31848100,40687400,51482925,64566684,80311266,99133020,121495355,147912160 %N A292350 Number of Lyndon words (aperiodic necklaces) with 6 beads of n colors. %H A292350 Colin Barker, <a href="/A292350/b292350.txt">Table of n, a(n) for n = 1..1000</a> %H A292350 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (7, -21, 35, -35, 21, -7, 1). %F A292350 a(n) = (n^6 - n^3 - n^2 + n)/6. %F A292350 From _Colin Barker_, Dec 08 2017: (Start) %F A292350 G.f.: x^2*(9 + 53*x + 47*x^2 + 11*x^3) / (1 - x)^7. %F A292350 a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n>7. %F A292350 (End) %o A292350 (PARI) concat(0, Vec(x^2*(9 + 53*x + 47*x^2 + 11*x^3) / (1 - x)^7 + O(x^40))) \\ _Colin Barker_, Dec 08 2017 %Y A292350 Row n=6 of A074650. %K A292350 nonn,easy %O A292350 1,2 %A A292350 _Eric M. Schmidt_, Dec 08 2017