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A132986 Triangle, read by rows, where row n of T = row n-1 of T^n (shift right 1 column) with T(n,0)=T(n,1) for n>0. 1
1, 1, 1, 2, 2, 1, 12, 12, 6, 1, 240, 240, 120, 24, 1, 18480, 18480, 9360, 2040, 120, 1, 6708240, 6708240, 3466080, 801360, 55440, 720, 1, 14088352320, 14088352320, 7423763760, 1792667520, 136972080, 2202480, 5040, 1, 203200845886080 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Table of n, a(n) for n=0..36.

EXAMPLE

Triangle begins:

1;

1, 1;

2, 2, 1;

12, 12, 6, 1;

240, 240, 120, 24, 1;

18480, 18480, 9360, 2040, 120, 1;

6708240, 6708240, 3466080, 801360, 55440, 720, 1;

14088352320, 14088352320, 7423763760, 1792667520, 136972080, 2202480, 5040, 1;

Matrix square T^2 begins:

1;

2, 1; <-- row 2 of T

6, 4, 1;

48, 36, 12, 1;

1248, 1008, 384, 48, 1;

127440, 108960, 45360, 6960, 240, 1; ...

Matrix cube T^3 begins:

1;

3, 1;

12, 6, 1; <-- row 3 of T

120, 72, 18, 1;

3840, 2592, 792, 72, 1;

486720, 359280, 125280, 14760, 360, 1; ...

Matrix fourth-power T^4 begins:

1;

4, 1;

20, 8, 1;

240, 120, 24, 1; <-- row 4 of T

9120, 5280, 1344, 96, 1;

1378560, 891840, 266400, 25440, 480, 1; ...

PROG

(PARI) {T(n, k)=local(M=if(n==0, [1], matrix(n+1, n+1, r, c, if(r>=c&r<=n, T(r-1, c-1))))); if(n==0, 1, if(k==0, T(n, 1), (M^n)[n, k]))}

CROSSREFS

Cf. A132987 (column 0).

Sequence in context: A100942 A132471 A130528 * A019112 A276851 A048660

Adjacent sequences:  A132983 A132984 A132985 * A132987 A132988 A132989

KEYWORD

nonn,tabl

AUTHOR

Paul D. Hanna, Sep 07 2007

STATUS

approved

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Last modified May 31 10:52 EDT 2020. Contains 334748 sequences. (Running on oeis4.)