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 A124313 #22 Feb 16 2025 08:33:03 %S A124313 1,0,0,0,1,2,3,6,12,24,47,92,181,356,700,1376,2705,5318,10455,20554, %T A124313 40408,79440,156175,307032,603609,1186664,2332920,4586400,9016625, %U A124313 17726218,34848827,68510990,134689060,264791720,520566815,1023407412 %N A124313 Pentanacci numbers: a(n) = a(n-1) + a(n-2) + a(n-3) + a(n-4) + a(n-5), starting 1,0,0,0,1. %H A124313 G. C. Greubel, <a href="/A124313/b124313.txt">Table of n, a(n) for n = 1..1000</a> %H A124313 I. Flores, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Scanned/5-3/flores.pdf">k-Generalized Fibonacci numbers</a>, Fib. Quart., 5 (1967), 258-266. %H A124313 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PentanacciNumber.html">Pentanacci Number</a> %H A124313 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (1,1,1,1,1). %F A124313 G.f.: x*(1-x-x^2-x^3)/(1-x-x^2-x^3-x^4-x^5). - Maksym Voznyy (voznyy(AT)mail.ru), Aug 12 2009; checked and corrected by _R. J. Mathar_, Sep 16 2009 %t A124313 f[n_]:= MatrixPower[{{1,1,1,1,1}, {1,0,0,0,0}, {0,1,0,0,0}, {0,0,1,0, 0}, {0,0,0,1,0}}, n][[ 1, 4]]; Array[f, 50] %t A124313 LinearRecurrence[{1,1,1,1,1}, {1,0,0,0,1}, 40] (* _G. C. Greubel_, Aug 25 2023 *) %o A124313 (Magma) R<x>:=PowerSeriesRing(Integers(), 40); Coefficients(R!( x*(1-2*x+x^4)/(1-2*x+x^6) )); // _G. C. Greubel_, Aug 25 2023 %o A124313 (SageMath) %o A124313 def A124313_list(prec): %o A124313 P.<x> = PowerSeriesRing(ZZ, prec) %o A124313 return P( (1-2*x+x^4)/(1-2*x+x^6) ).list() %o A124313 A124313_list(50) # _G. C. Greubel_, Aug 25 2023 %Y A124313 Cf. A001591, A124312, A124314. %K A124313 nonn,easy %O A124313 1,6 %A A124313 _Artur Jasinski_, Oct 25 2006 %E A124313 Edited by _Ralf Stephan_, Oct 20 2013