A113386 - OEIS

%I #5 Jun 13 2017 23:29:56

%S 1,10,130,2365,57695,1798275,68931064,3155772612,168671241316,

%T 10336797449013,715846906453760,55355481111622706,4732541017570608210,

%U 443593124488673026361,45261577596891190335258

%N Column 1 of triangle A113384, also equals column 0 of A113381^5.

%F A113384 equals the matrix square of A113381, which has the property: column k of A113381^2 = column 0 of A113381^(3*k+2) for k>=0.

%o (PARI) a(n)=local(A,B);A=Mat(1);for(m=2,n+2,B=matrix(m,m); for(i=1,m, for(j=1,i,if(i<3 || j==i || j>m-1,B[i,j]=1,if(j==1, B[i,1]=1,B[i,j]=(A^(3*j-2))[i-j+1,1]));));A=B); (matrix(#A,#A,r,c,if(r>=c,(A^(3*c-1))[r-c+1,1]))^2)[n+2,2]

%Y Cf. A113381, A113384, A113385 (column 0).

%K nonn

%O 0,2

%A _Paul D. Hanna_, Nov 14 2005