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 A017023 #18 Oct 17 2023 18:24:38
%S A017023 2187,10000000,410338673,4586471424,27512614111,114415582592,
%T A017023 373669453125,1028071702528,2488651484819,5455160701056,
%U A017023 11047398519097,20971520000000,37725479487783,64847759419264
%N A017023 a(n) = (7*n + 3)^7.
%H A017023 Vincenzo Librandi, <a href="/A017023/b017023.txt">Table of n, a(n) for n = 0..10000</a>
%H A017023 <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 A017023 From _G. C. Greubel_, Oct 17 2023: (Start)
%F A017023 G.f.: (2187 + 9982504*x + 330399909*x^2 + 1583639568*x^3 + 1750478653*x^4 + 456781416*x^5 + 19356099*x^6 + 16384*x^7)/(1-x)^8.
%F A017023 E.g.f.: (2187 + 9997813*x + 195170430*x^2 + 564242203*x^3 + 482865110*x^4 + 155531978*x^5 + 19765032*x^6 + 823543*x^7)*exp(x). (End)
%t A017023 (7*Range[0,30]+3)^7 (* or *) LinearRecurrence[{8,-28,56,-70,56,-28, 8,-1}, {2187,10000000,410338673,4586471424,27512614111,114415582592, 373669453125,1028071702528}, 30] (* _Harvey P. Dale_, Jul 07 2020 *)
%o A017023 (Magma) [(7*n+3)^7: n in [0..30]]; // _Vincenzo Librandi_, Jul 14 2011
%o A017023 (SageMath) [(7*n+3)^7 for n in range(41)] # _G. C. Greubel_, Oct 17 2023
%Y A017023 Cf. A017017 - A017022, A017024 - A017028.
%K A017023 nonn,easy
%O A017023 0,1
%A A017023 _N. J. A. Sloane_