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A234944 Array read by antidiagonals: T(i,j) = number of different optimal difference triangle sets M(i,j). 3
1, 1, 1, 1, 3, 1, 1, 12, 2, 2, 1, 8, 9, 1, 4, 1, 21, 12, 4, 2, 5, 1, 720, 174, 6, 3, 2, 1, 1, 4079, 3132, 92, 1, 4, 1, 1, 1, 3040, 71930, 117 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

This array gives the number of different ways to choose the optimal difference triangle sets M(i,j) described in A234943.

LINKS

Table of n, a(n) for n=1..40.

J. B. Shearer, Difference Triangle Sets: Known optimal solutions.

J. B. Shearer, Difference Triangle Sets: Discoverers

EXAMPLE

Array begins:

j\i| 1,  2,  3,   4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,

-----------------------------------------------------------------

1  | 1,   1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,   1,   1 (A000012)

2  | 1,   3,   12,   8,  21, 720, 4079, 3040, 20505, 1669221, 14708525, 10567748,  (A234947)

3  | 1,   2,    9,  12, 174, 3132, 71930,   (A234945)

4  | 2,   1,    4,   6,  92, 117,   (A234946)

5  | 4,   2,    3,   1,

6  | 5,   2,    4,   4,

7  | 1,   1,    1,

8  | 1,   2,

9  | 1,   1,

10 | 2,

11 | 1

12 | 1

13 | 1

14 | 1

15 | 1

The entries match those in A234943.

CROSSREFS

Rows give A234947, A234945, A234946.

Cf. A234943.

Sequence in context: A176421 A168552 A111473 * A067402 A113340 A134523

Adjacent sequences:  A234941 A234942 A234943 * A234945 A234946 A234947

KEYWORD

nonn,tabl,more

AUTHOR

N. J. A. Sloane, Jan 08 2014

STATUS

approved

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Last modified August 5 08:27 EDT 2021. Contains 346464 sequences. (Running on oeis4.)