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 A270872 #16 Jan 14 2023 12:02:31
%S A270872 13,2278,19439,117910,550009,2072078,6584443,18269614,45445445,
%T A270872 103390294,218437543,433677158,816642289,1469399230,2541499379,
%U A270872 4246292158,6881138173,10852102214,16703746015,25154681014,37139581673,53858400238,76833564139,107975977550
%N A270872 a(n) = n^8 + 7*n^7 + 34*n^6 + 111*n^5 + 275*n^4 + 511*n^3 + 703*n^2 + 623*n + 13.
%H A270872 Vincenzo Librandi, <a href="/A270872/b270872.txt">Table of n, a(n) for n = 0..1000</a>
%H A270872 Andrew Misseldine, <a href="http://arxiv.org/abs/1508.03757">Counting Schur Rings over Cyclic Groups</a>, arXiv preprint arXiv:1508.03757 [math.RA], 2015. (page 19, 4th row; page 21, 8th row).
%H A270872 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (9,-36,84,-126,126,-84,36,-9,1).
%F A270872 G.f.: (13+2161*x-595*x^2+23875*x^3-1091*x^4+19271*x^5-4997*x^6+1909*x^7-226*x^8)/(1-x)^9.
%F A270872 a(n) = 9*a(n-1) - 36*a(n-2) + 84*a(n-3) - 126*a(n-4) + 126*a(n-5) - 84*a(n-6) + 36*a(n-7) - 9*a(n-8) + a(n-9).
%t A270872 Table[n^8 + 7 n^7 + 34 n^6 + 111 n^5 + 275 n^4 + 511 n^3 + 703 n^2 + 623 n + 13, {n, 0, 40}]
%t A270872 LinearRecurrence[{9,-36,84,-126,126,-84,36,-9,1},{13,2278,19439,117910,550009,2072078,6584443,18269614,45445445},30] (* _Harvey P. Dale_, Jan 14 2023 *)
%o A270872 (Magma) [n^8+7*n^7+34*n^6+111*n^5+275*n^4+511*n^3+703*n^2+623*n+13: n in [0..40]];
%o A270872 (PARI) x='x+O('x^99); Vec((13+2161*x-595*x^2+23875*x^3-1091*x^4+19271*x^5-4997*x^6+1909*x^7-226*x^8)/(1-x)^9) \\ _Altug Alkan_, Apr 04 2016
%Y A270872 Cf. A270867, A270868, A270869, A270870, A270871.
%K A270872 nonn,easy
%O A270872 0,1
%A A270872 _Vincenzo Librandi_, Apr 04 2016