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 A179098 #17 Aug 03 2022 07:35:11 %S A179098 0,1,28,266,1428,5475,16808,44052,102552,217701,429220,796510,1405196, %T A179098 2374983,3868944,6104360,9365232,14016585,20520684,29455282,41534020, %U A179098 57629099,78796344,106302780,141656840,186641325,243349236,314222598 %N A179098 Rectified 7-simplex number: the coefficient of x^(2n-2) in (1+x+x^2+...+x^(n-1))^8. %H A179098 J. Conrad, <a href="/A179098/b179098.txt">Table of n, a(n) for n = 0..34</a> %H A179098 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (8,-28,56,-70,56,-28,8,-1). %F A179098 Conjectures: a(n) = n*(90+77*n+140*n^3+210*n^4+98*n^5+15*n^6)/630. G.f.: x*(1+20*x+70*x^2+28*x^3+x^4)/(1-x)^8. - _Colin Barker_, Jan 09 2012 %F A179098 These conjectures are true, see A179095 for proof. %t A179098 f[n_] := CoefficientList[ Series[ Sum[ x^k, {k, 0, n - 1}]^8, {x, 0, 2 n + 3}], x][[2 n - 1]]; Array[f, 33] (* _Robert G. Wilson v_, Jul 30 2010 *) %o A179098 (PARI) a(n) = polcoeff(((x^n-1)/(x-1))^8, 2*n-2); \\ _Michel Marcus_, Feb 17 2016 %Y A179098 Cf. A179095, A179096, A179097, A179099. %K A179098 nonn %O A179098 0,3 %A A179098 _Michael A. Jackson_, Jun 29 2010 %E A179098 More terms from _Robert G. Wilson v_, Jul 30 2010