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A051601 Rows of triangle formed using Pascal's rule except we begin and end the n-th row with n. 1
0, 1, 1, 2, 2, 2, 3, 4, 4, 3, 4, 7, 8, 7, 4, 5, 11, 15, 15, 11, 5, 6, 16, 26, 30, 26, 16, 6, 7, 22, 42, 56, 56, 42, 22, 7, 8, 29, 64, 98, 112, 98, 64, 29, 8, 9, 37, 93, 162, 210, 210, 162, 93, 37, 9, 10, 46, 130, 255, 372, 420, 372, 255, 130, 46 (list; table; graph; refs; listen; history; internal format)
OFFSET

0,4

COMMENTS

The number of spotlight tilings of an m-by-n rectangle missing the southeast corner. E.g. there are 2 spotlight tilings of a 2 X 2 square missing its southeast corner. - Bridget Eileen Tenner (bridget(AT)math.depaul.edu), Nov 10 2007

REFERENCES

B. E. Tenner, <a href="http://dx.doi.org/10.1007/s00026-011-0077-6">Spotlight tiling</a>, Ann. Combinat. 14 (4) (2010) 553-568.

FORMULA

T(m,n) = binomial(m+n,m) - 2*binomial(m+n-2,m-1), up to offset and transformation of array to triangular indices. - Bridget Eileen Tenner (bridget(AT)math.depaul.edu), Nov 10 2007

t(n,k)= Binomial[n, k + 1] + Binomial[n, n - k + 1]. [From Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Feb 17 2009]

EXAMPLE

Contribution from Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Feb 17 2009: (Start)

0;

1, 1;

2, 2, 2;

3, 4, 4, 3;

4, 7, 8, 7, 4;

5, 11, 15, 15, 11, 5;

6, 16, 26, 30, 26, 16, 6;

7, 22, 42, 56, 56, 42, 22, 7;

8, 29, 64, 98, 112, 98, 64, 29, 8;

9, 37, 93, 162, 210, 210, 162, 93, 37, 9;

10, 46, 130, 255, 372, 420, 372, 255, 130, 46, 10;

11, 56, 176, 385, 627, 792, 792, 627, 385, 176, 56, 11;

12, 67, 232, 561, 1012, 1419, 1584, 1419, 1012, 561, 232, 67, 12; (End)

MATHEMATICA

Contribution from Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Feb 17 2009: (Start)

t[n_, k_] = Binomial[n, k + 1] + Binomial[n, n - k + 1];

Table[Table[t[n, k], {k, 0, n}], {n, 0, 12}];

Flatten[%] (End)

CROSSREFS

Row sums give A000918(n+1).

Sequence in context: A096009 A000224 A085201 * A193921 A074829 A060243

Adjacent sequences:  A051598 A051599 A051600 * A051602 A051603 A051604

KEYWORD

easy,nonn,tabl

AUTHOR

Asher Auel (asher.auel(AT)reed.edu)

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Last modified February 17 22:48 EST 2012. Contains 206085 sequences.