OFFSET
0,4
FORMULA
[T^n](n,k) = (n-k)!*C(n,k)*C(n^2,n-k) gives the k-th term of the n-th row of the n-th matrix power of this triangle T. [From Paul D. Hanna, Feb 13 2010]
EXAMPLE
Triangle T begins:
1;
1,1;
4,4,1;
84,36,9,1;
4584,1056,144,16,1;
469440,73200,6000,400,25,1;
76982940,9179640,537300,22800,900,36,1;
18391183020,1794887640,83163780,2598960,67620,1764,49,1;
6011375932800,500614248960,19475406720,492038400,9619680,169344,3136,64,1;
2570927357779200,187826632116480,6361668149760,137161382400,2198871360,29502144,374976,5184,81,1;
...
Generator triangle I+D, with diagonal D(n+1,n)=n+1, begins:
1;
1,1;
0,2,1;
0,0,3,1;
0,0,0,4,1;
...
ILLUSTRATE: row n of T^n = row n of (I+D)^(n^2).
For n=2, matrix square T^2 begins:
1;
2,1;
12,8,1; <== row 2 of T^2
240,108,18,1;
12144,3264,432,32,1;
...
while (I+D)^4 begins:
1;
4,1;
12,8,1; <== row 2 of (I+D)^4 = row 2 of T^2
24,36,12,1;
24,96,72,16,1;
...
For n=3, matrix cube T^3 begins:
1;
3,1;
24,12,1;
504,216,27,1; <== row 3 of T^3
24408,7200,864,48,1;
...
while (I+D)^9 begins:
1;
9,1;
72,18,1;
504,216,27,1; <== row 3 of (I+D)^9 = row 3 of T^3
3024,2016,432,36,1;
...
For n=4, matrix power T^4 begins:
1;
4,1;
40,16,1;
912,360,36,1;
43680,13440,1440,64,1; <== row 4 of T^4
...
while (I+D)^16 begins:
1;
16,1;
240,32,1;
3360,720,48,1;
43680,13440,1440,64,1; <== row 4 of (I+D)^16 = row 4 of T^4
...
PROG
(PARI) {T(n, k)=local(M=Mat(1), N, L, C=matrix(n+1, n+1, r, c, if(r==c, 1, if(r==c+1, c)))); for(i=1, n, N=M; M=matrix(#N+1, #N+1, r, c, if(r>=c, if(r<=#N, (N^(#N))[r, c], (C^((#M)^2))[r, c]))); L=sum(i=1, #M, -(M^0-M)^i/i); M=sum(i=0, #M, (L/#N)^i/i!); ); M[n+1, k+1]}
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Paul D. Hanna, Feb 12 2010
STATUS
approved