A113108 - OEIS

%I #3 Mar 30 2012 18:36:51

%S 1,2,1,16,12,1,440,416,62,1,43600,48320,10016,312,1,16698560,20765520,

%T 5394320,246016,1562,1,26098464448,35382716032,10854556720,646408320,

%U 6116016,7812,1,172513149018752,250136469031744,87213434633152

%N Triangle T, read by rows, equal to the matrix square of triangle A113106, which satisfies the recurrence: A113106(n,k) = [A113106^5](n-1,k-1) + [A113106^5](n-1,k).

%e Triangle begins:

%e 1;

%e 2,1;

%e 16,12,1;

%e 440,416,62,1;

%e 43600,48320,10016,312,1;

%e 16698560,20765520,5394320,246016,1562,1;

%e 26098464448,35382716032,10854556720,646408320,6116016,7812,1; ...

%o (PARI) {T(n,k)=local(M=matrix(n+1,n+1));for(r=1,n+1, for(c=1,r, M[r,c]=if(r==c,1,if(c>1,(M^5)[r-1,c-1])+(M^5)[r-1,c]))); return((M^2)[n+1,k+1])}

%Y Cf. A113106.

%K nonn,tabl

%O 0,2

%A _Paul D. Hanna_, Oct 14 2005