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 A105332 #19 Apr 18 2025 14:31:22 %S A105332 0,1,3,6,2,7,5,4,4,5,7,2,6,3,1,0,0,1,3,6,2,7,5,4,4,5,7,2,6,3,1,0,0,1, %T A105332 3,6,2,7,5,4,4,5,7,2,6,3,1,0,0,1,3,6,2,7,5,4,4,5,7,2,6,3,1,0,0,1,3,6, %U A105332 2,7,5,4,4,5,7,2,6,3,1,0,0,1,3,6,2,7,5,4,4,5,7,2,6,3,1,0,0,1,3,6,2,7,5,4,4 %N A105332 a(n) = n*(n+1)/2 mod 8. %C A105332 Periodic with period length 16. - _Ray Chandler_, Apr 18 2025 %H A105332 <a href="/index/Rec#order_15">Index entries for linear recurrences with constant coefficients</a>, signature (1,-1,1,-1,1,-1,1,-1,1,-1,1,-1,1,-1,1). %t A105332 Mod[Accumulate[Range[0,110]],8] (* _Harvey P. Dale_, Nov 03 2013 *) %o A105332 (Python) %o A105332 def A105332(n): return (n*(n+1)>>1)&7 # _Chai Wah Wu_, Apr 17 2025 %Y A105332 Cf. A000217. %Y A105332 See A105198 for further information. %K A105332 nonn,easy %O A105332 0,3 %A A105332 _Oscar Takeshita_, May 01 2005