%I
%S 1,2,4,16,32,128,512,4096,8192,32768,131072,1048576,4194304,
%T 33554432,268435456,4294967296,8589934592,34359738368,
%U 137438953472,1099511627776,4398046511104,35184372088832,281474976710656
%N Determinant of n X n partial Hadamard matrix with coefficient m(i,j) 1<=i,j<=n (see comment).
%C 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(k1)M(k1) M(k)= M(k1)M(k1)
%F 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 ?
%e M(2)=/1,1/1,1/ then a(2)=detM(2)=2
%K sign
%O 1,2
%A _Benoit Cloitre_, Jun 03 2004
