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 A054527 #16 Feb 06 2022 10:08:17 %S A054527 1,1,-1,1,-1,-1,1,-1,-1,0,1,-1,-1,0,-1,1,-1,-1,0,-1,1,1,-1,-1,0,-1,1, %T A054527 -1,1,-1,-1,0,-1,1,-1,0,1,-1,-1,0,-1,1,-1,0,0,1,-1,-1,0,-1,1,-1,0,0,1, %U A054527 1,-1,-1,0,-1,1,-1,0,0,1,-1,1,-1,-1,0,-1,1,-1,0,0,1,-1,0,1,-1,-1,0,-1,1,-1,0,0,1,-1,0,-1,1,-1 %N A054527 Triangle read by rows: T(n,k) = Moebius mu(k) (n >= 1, 1 <= k <= n). %C A054527 Row sums = Mertens sequence = A002321; right border = mu(n) = A008683. - _Gary W. Adamson_, Jan 17 2007 %C A054527 M * Q as infinite lower triangular matrices; M = (1; 1, 1; 1, 1, 1; ...); Q = mu(n) in the main diagonal and the rest zeros. - _Gary W. Adamson_, Jan 17 2007 %C A054527 Terms in rows of this table appears to be the values of the minors in the first expansion of the determinant of the Redheffer matrix. - _Mats Granvik_, Aug 24 2008 %H A054527 Reinhard Zumkeller, <a href="/A054527/b054527.txt">Rows n = 1..125 of triangle, flattened</a> %e A054527 First few rows of the triangle: %e A054527 1; %e A054527 1, -1; %e A054527 1, -1, -1; %e A054527 1, -1, -1, 0; %e A054527 1, -1, -1, 0, -1; %e A054527 1, -1, -1, 0, -1, 1; %e A054527 ... %t A054527 Table[#[[1 ;; n]], {n, Length[#]}] &@ Array[MoebiusMu, 12] // Flatten (* _Michael De Vlieger_, Feb 05 2022 *) %o A054527 (Haskell) %o A054527 import Data.List (inits) %o A054527 a054527 n k = a054527_tabl !! (n-1) !! (k-1) %o A054527 a054527_row n = a054527_tabl !! (n-1) %o A054527 a054527_tabl = tail $ inits a008683_list %o A054527 -- _Reinhard Zumkeller_, Sep 03 2015 %Y A054527 Cf. A008683, A002321, A054521. %K A054527 sign,tabl %O A054527 1,1 %A A054527 _N. J. A. Sloane_, Apr 09 2000 %E A054527 Edited by _N. J. A. Sloane_, Jul 03 2008 at the suggestion of _R. J. Mathar_