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A113392 Triangle, read by rows, equal to the matrix square of triangle A113389. Also given by the matrix product: R^2 = Q^3*(P^-2)*Q, using triangular matrices P=A113370, Q=A113381 and R=A113389. 5
1, 6, 1, 48, 12, 1, 605, 186, 18, 1, 11196, 3892, 414, 24, 1, 280440, 106089, 12021, 732, 30, 1, 8981460, 3620379, 429345, 27152, 1140, 36, 1, 353283128, 149740555, 18386361, 1196910, 51445, 1638, 42, 1, 16567072675, 7316974618, 923656512 (list; table; graph; refs; listen; history; internal format)
OFFSET

0,2

EXAMPLE

Triangle A113389^2 begins:

1;

6,1;

48,12,1;

605,186,18,1;

11196,3892,414,24,1;

280440,106089,12021,732,30,1;

8981460,3620379,429345,27152,1140,36,1;

353283128,149740555,18386361,1196910,51445,1638,42,1;

16567072675,7316974618,923656512,61515702,2696010,87060,2226,48,1;

PROG

(PARI) {T(n, k)=local(A, B); A=Mat(1); for(m=2, n+1, 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))[r-c+1, 1]))^2)[n+1, k+1]}

CROSSREFS

Cf. A113389, A113388 (column 0), A113393 (column 1).

Sequence in context: A049374 A138192 A136235 * A113387 A090435 A136237

Adjacent sequences:  A113389 A113390 A113391 * A113393 A113394 A113395

KEYWORD

nonn,tabl

AUTHOR

Paul D. Hanna (pauldhanna(AT)juno.com), Nov 14 2005

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Last modified February 16 21:51 EST 2012. Contains 205978 sequences.