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 A008593 #74 Apr 10 2025 16:35:06 %S A008593 0,11,22,33,44,55,66,77,88,99,110,121,132,143,154,165,176,187,198,209, %T A008593 220,231,242,253,264,275,286,297,308,319,330,341,352,363,374,385,396, %U A008593 407,418,429,440,451,462,473,484,495,506,517,528,539,550,561,572,583 %N A008593 Multiples of 11. %C A008593 Numbers for which the sum of "digits" in base 100 is divisible by 11. For instance, 193517302 gives 1 + 93 + 51 + 73 + 02 = 220, and 2 + 20 = 22 = 2 * 11. - _Daniel Forgues_, Feb 22 2016 %C A008593 Numbers in which the sum of the digits in the even positions equals the sum of the digits in the odd positions. - _Stefano Spezia_, Jan 05 2025 %H A008593 Vincenzo Librandi, <a href="/A008593/b008593.txt">Table of n, a(n) for n = 0..10000</a> %H A008593 INRIA Algorithms Project, <a href="http://ecs.inria.fr/services/structure?nbr=323">Encyclopedia of Combinatorial Structures 323</a>. %H A008593 Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a>. %H A008593 Luis Manuel Rivera, <a href="http://arxiv.org/abs/1406.3081">Integer sequences and k-commuting permutations</a>, arXiv preprint arXiv:1406.3081 [math.CO], 2014-2015. %H A008593 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1). %F A008593 a(n) = 11*n. %F A008593 G.f.: 11*x/(1-x)^2. - _David Wilding_, Jun 21 2014 %F A008593 E.g.f.: 11*x*exp(x). - _Stefano Spezia_, Oct 08 2022 %F A008593 From _Elmo R. Oliveira_, Apr 10 2025: (Start) %F A008593 a(n) = 2*a(n-1) - a(n-2). %F A008593 a(n) = A008604(n)/2. (End) %p A008593 g:=(1+10*z)/((1-z)): gser:=series(g, z=0, 88): seq((coeff(gser, z, n))*n, n=0..77); # _Zerinvary Lajos_, Feb 25 2009 %t A008593 Range[0, 1000, 11] (* _Vladimir Joseph Stephan Orlovsky_, May 28 2011 *) %o A008593 (Magma) [11*n: n in [0..60]]; // _Vincenzo Librandi_, Sep 18 2011 %o A008593 (Maxima) makelist(11*n,n,0,20); /* _Martin Ettl_, Dec 17 2012 */ %o A008593 (Haskell) %o A008593 a008593 = (* 11) %o A008593 a008593_list = [0, 11 ..] -- _Reinhard Zumkeller_, Jul 05 2014 %o A008593 (PARI) a(n)=11*n \\ _Charles R Greathouse IV_, Nov 06 2014 %Y A008593 Cf. A008591, A008592, A008604, A059632; union of A135499 and A060979. %K A008593 nonn,easy %O A008593 0,2 %A A008593 _N. J. A. Sloane_