A059681 Triangle T(n,k) giving number of fixed 5 X k polyominoes with n cells (n >= 5, 1<=k<=n-4).

1, 0, 16, 0, 38, 83, 0, 32, 376, 230, 0, 10, 784, 1526, 497, 0, 1, 987, 5154, 4180, 932, 0, 0, 778, 11328, 18944, 9458, 1591, 0, 0, 370, 17598, 58665, 52488, 18936, 2538, 0, 0, 101, 19912, 135325, 204466, 123652, 34726, 3845, 0, 0, 15, 16440, 241550, 611859

Offset

5,3

Links

Andrew Howroyd, Table of n, a(n) for n = 5..1279

R. C. Read, Contributions to the cell growth problem, Canad. J. Math., 14 (1962), 1-20.

Formula

T(n,k) = 0 for n > 5*k. - Andrew Howroyd, Oct 02 2017

Example

Triangle starts:
1;
0, 16;
0, 38,  83;
0, 32, 376,   230;
0, 10, 784,  1526,   497;
0,  1, 987,  5154,  4180,  932;
0,  0, 778, 11328, 18944, 9458, 1591;
...

Crossrefs

Column sums are row 5 of A292357.

Cf. A059678, A059679, A059680.

Sequence in context: A005077 A059060 A331140 * A135925 A188784 A123935

Adjacent sequences: A059678 A059679 A059680 * A059682 A059683 A059684

Keyword

nonn,easy,nice,tabl

Author

N. J. A. Sloane, Feb 05 2001

Extensions

a(24) corrected and terms a(26) and beyond from Andrew Howroyd, Oct 02 2017

Status

approved