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 A105336 #7 Apr 18 2025 14:38:45 %S A105336 0,1,3,6,10,15,21,28,36,45,55,66,78,91,105,120,8,25,43,62,82,103,125, %T A105336 20,44,69,95,122,22,51,81,112,16,49,83,118,26,63,101,12,52,93,7,50,94, %U A105336 11,57,104,24,73,123,46,98,23,77,4,60,117,47,106,38,99,33,96,32,97,35,102,42 %N A105336 a(n) = n*(n+1)/2 mod 128. %C A105336 Periodic with period length 256. - _Ray Chandler_, Apr 18 2025 %H A105336 <a href="/index/Rec#order_255">Index entries for linear recurrences with constant coefficients</a>, order 255. %t A105336 Mod[Accumulate[Range[0,70]],128] (* _Harvey P. Dale_, Oct 16 2013 *) %Y A105336 See A105198 for further information. %K A105336 nonn %O A105336 0,3 %A A105336 _Oscar Takeshita_, May 01 2005