%I A102226
%S A102226 1,1,2,3,7,17,75,346,4874,49047,3009094,69540959,19266759978,
%T A102226 1145861630146,1316021940482105,231957006949639674,
%U A102226 1000756528918141445755,578298169571294295021140
%N A102226 Column 0 of triangular matrix A102225, in which row k is formed from 
               the first differences of row (k-1) of its matrix square (A102228).
%C A102226 Also equals column 0 of A102228 shift one place right.
%F A102226 a(n) = A102229(n-1) - A102227(n) for n>=2, where A102227 equals column 
               1 of A102225 and A102229 equals column 1 of A102228.
%o A102226 (PARI) {a(n)=local(A=matrix(1,1),B);A[1,1]=1; for(m=2,n+1,B=matrix(m,
               m);for(i=1,m, for(j=1,i, if(j==i,B[i,j]=1,if(j==1,B[i,j]=(A^2)[i-1,
               1], B[i,j]=(A^2)[i-1,j]-(A^2)[i-1,j-1]));));A=B);return(A[n+1,1])}
%Y A102226 Cf. A102225, A102227, A102228, A102229.
%Y A102226 Sequence in context: A143013 A113483 A059801 this_sequence A058334 A131093 
               A002864
%Y A102226 Adjacent sequences: A102223 A102224 A102225 this_sequence A102227 A102228 
               A102229
%K A102226 nonn
%O A102226 0,3
%A A102226 Paul D. Hanna (pauldhanna(AT)juno.com), Jan 01 2005