1,2

Let M(infinity) be the infinite matrix with coefficient m(i,j) i>=1, j>=1 defined as follows : M(0)=1 and M(k) is the 2^k X 2^k matrix following the recursion : +M(k-1)-M(k-1) M(k)= -M(k-1)-M(k-1)

Table of n, a(n) for n=1..23.

It appears that abs(a(n))=2^A000788(n). What is the rule for signs? Does sum(k=1, n, a(k+1)/a(k))=0 iff n is in A073536 ?

M(2)=/1,-1/-1,-1/ then a(2)=detM(2)=-2

Sequence in context: A145119 A081411 A269758 * A053038 A001088 A101926

Adjacent sequences: A094381 A094382 A094383 * A094385 A094386 A094387

sign

Benoit Cloitre, Jun 03 2004

approved