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 A180051 #2 Mar 30 2012 18:53:10 %S A180051 1,-1,1,0,-1,1,-1,-1,3,1,-1,-1,6,3,1,-2,-1,15,7,3,1,-1,-1,31,15,7,3,1, %T A180051 -2,-1,72,34,16,7,3,1,-2,-1,157,73,34,16,7,3,1,-2,-1,347,161,75,35,16, %U A180051 7,3,1,-1,-1,751,349,162,75,35,16,7,3,1,-2,-1,1645,763,354,164,76,35,16,7 %N A180051 Triangle T(n,k) read by rows. Matrix inverse of A180050. %C A180051 At n>3, k=1 T(n,k)=A002321(n-1). It could perhaps be said that the Mertens function is an invariant under the recurrence in A180050 and matrix inversion. %e A180051 Table begins: %e A180051 1, %e A180051 -1,1, %e A180051 0,-1,1, %e A180051 -1,-1,3,1, %e A180051 -1,-1,6,3,1, %e A180051 -2,-1,15,7,3,1, %e A180051 -1,-1,31,15,7,3,1, %e A180051 -2,-1,72,34,16,7,3,1, %e A180051 -2,-1,157,73,34,16,7,3,1, %e A180051 -2,-1,347,161,75,35,16,7,3,1, %e A180051 -1,-1,751,349,162,75,35,16,7,3,1, %e A180051 -2,-1,1645,763,354,164,76,35,16,7,3,1, %e A180051 -2,-1,3553,1646,763,354,164,76,35,16,7,3,1, %e A180051 -3,-1,7720,3576,1657,768,356,165,76,35,16,7,3,1, %Y A180051 Cf. A002321, A180050. %K A180051 sign,tabl %O A180051 1,9 %A A180051 _Mats Granvik_, Aug 08 2010