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 A124356 #34 Feb 16 2025 08:33:03 %S A124356 2,8,6,12,10,16,14,20,18,24,22,28,26,32,30,36,34,40,38,44,42,48,46,52, %T A124356 50,56,54,60,58,64,62,68,66,72,70,76,74,80,78,84,82,88,86,92,90,96,94, %U A124356 100,98,104,102,108,106,112,110,116,114,120,118,124,122,128,126,132 %N A124356 Number of (directed) Hamiltonian cycles on the Moebius ladder graph M_n (for n>=4). %H A124356 Vincenzo Librandi, <a href="/A124356/b124356.txt">Table of n, a(n) for n = 1..10000</a> %H A124356 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/HamiltonianCycle.html">Hamiltonian Cycle</a> %H A124356 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MoebiusLadder.html">Moebius Ladder</a> %H A124356 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (1,1,-1). %F A124356 a(n odd) = 2*n, a(n even) = 2*n+4. %F A124356 a(n) = 2(n+1)+2(-1)^n. - _Paul Barry_, Feb 17 2008 %F A124356 a(n) -a(n-4) = 8. - _Paul Curtz_, Apr 19 2011 %F A124356 a(n) = +1*a(n-1) +1*a(n-2) -1*a(n-3). - _Joerg Arndt_, Apr 22 2011 %F A124356 G.f.: 2*x*(1+3*x-2*x^2)/((1-x)^2*(1+x)). - _Colin Barker_, Jan 23 2012 %F A124356 a(n) = 2*A014681(n+1). - _R. J. Mathar_, Nov 27 2015 %o A124356 (Magma) [2*(n+1)+2*(-1)^n: n in [1..70]]; // _Vincenzo Librandi_, Aug 11 2011 %K A124356 nonn,easy %O A124356 1,1 %A A124356 _Eric W. Weisstein_, Nov 05 2006