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 A178513 #34 Apr 08 2024 17:48:05 %S A178513 1,81,6481,518481,41478481,3318278481,265462278481,21236982278481, %T A178513 1698958582278481,135916686582278481,10873334926582278481, %U A178513 869866794126582278481,69589343530126582278481,5567147482410126582278481,445371798592810126582278481 %N A178513 Partial sums of 80^n. %C A178513 Related to backward decimal expansion of fraction 1/79 and Pell numbers. [In which way? - _Joerg Arndt_, May 17 2011] %H A178513 Vincenzo Librandi, <a href="/A178513/b178513.txt">Table of n, a(n) for n = 0..150</a> %H A178513 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (81,-80). %F A178513 a(n) = 80*a(n-1) + 1. %F A178513 a(n) = (80^(n+1)-1)/79. %F A178513 G.f.: 1/((1-80*x)*(1-x)). %t A178513 Accumulate[80^Range[0,20]] (* _Harvey P. Dale_, Aug 11 2014 *) %Y A178513 Cf. A000129, A021083, A038207, A178510, A178511, A178512. %K A178513 nonn,easy %O A178513 0,2 %A A178513 _Mark Dols_, May 29 2010