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 A105337 #7 Apr 18 2025 14:40:12 %S A105337 0,1,3,6,10,15,21,28,36,45,55,66,78,91,105,120,136,153,171,190,210, %T A105337 231,253,20,44,69,95,122,150,179,209,240,16,49,83,118,154,191,229,12, %U A105337 52,93,135,178,222,11,57,104,152,201,251,46,98,151,205,4,60,117,175,234,38,99 %N A105337 a(n) = n*(n+1)/2 mod 256. %C A105337 Periodic with period length 512. - _Ray Chandler_, Apr 18 2025 %H A105337 <a href="/index/Rec#order_511">Index entries for linear recurrences with constant coefficients</a>, order 511. %t A105337 Mod[Accumulate[Range[0,70]],256] (* _Harvey P. Dale_, Nov 20 2020 *) %Y A105337 See A105198 for further information. %K A105337 nonn %O A105337 0,3 %A A105337 _Oscar Takeshita_, May 01 2005