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 A141446 #6 Oct 04 2015 00:04:59 %S A141446 1,2,1,4,-4,7,-5,8,-5,4,-7,1,-5,5,-2,4,-1,4,-5,2,-8,4,-4,7,-5,8,-5,4, %T A141446 -7,1,-5,5,-2,4,-1,4,-5,2,-8,4,-4,7,-5,8,-5,4,-7,1,-5,5,-2,4,-1,4,-5, %U A141446 2,-8,4,-4,7,-5,8,-5,4,-7,1,-5,5,-2,4,-1,4,-5,2,-8,4,-4,7,-5,8,-5,4,-7,1,-5,5 %N A141446 A102055(n) mod 9. %C A141446 We compute the positive remainder modulo 9 and subtract 9 if A102055(n) is negative. %C A141446 Appears to be periodic with period length 18 after the transitional first 3 elements. (This would imply only the same 6 digits appear as found in A141425.) %F A141446 a(3n) + a(3n+1) + a(3n+2) = 4, 7, -2, -2, -2, 5 ever same six digits? %p A141446 A102055 := proc(n) local k; if n = 0 then 1; else 1-add(A001469(k),k=1..n) ; end if; end proc: %p A141446 A141446 := proc(n) local a; a := A102055(n) ; if a > 0 then a mod 9; else (a mod 9)-9; end if; end proc; # _R. J. Mathar_, Jul 07 2011 %Y A141446 Cf. A141430. %K A141446 sign %O A141446 0,2 %A A141446 _Paul Curtz_, Aug 07 2008