A059680 Triangle T(n,k) read by rows giving number of fixed 4 X k polyominoes with n cells (n >= 4, 1<=k<=n-3).

1, 0, 12, 0, 18, 50, 0, 8, 154, 120, 0, 1, 212, 584, 230, 0, 0, 158, 1396, 1526, 388, 0, 0, 62, 2038, 5154, 3276, 602, 0, 0, 12, 1952, 11328, 14192, 6194, 880, 0, 0, 1, 1232, 17598, 41196, 32824, 10704, 1230, 0, 0, 0, 488, 19912, 87980, 117616, 67284, 17294, 1660

Offset

4,3

Links

Andrew Howroyd, Table of n, a(n) for n = 4..1278

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

Formula

T(n,k) = 0 for n > 4*k. - Andrew Howroyd, Oct 02 2017

Example

Triangle starts:
1;
0, 12;
0, 18,  50;
0,  8, 154,  120;
0,  1, 212,  584,   230;
0,  0, 158, 1396,  1526,   388;
0,  0,  62, 2038,  5154,  3276,  602;
0,  0,  12, 1952, 11328, 14192, 6194, 880;
...

Crossrefs

Column sums are A034187.

Cf. A059678, A059679, A059681, A059684.

Sequence in context: A307163 A254526 A156390 * A307170 A332053 A225951

Adjacent sequences: A059677 A059678 A059679 * A059681 A059682 A059683

Keyword

nonn,easy,nice,tabl

Author

N. J. A. Sloane, Feb 05 2001

Extensions

Terms a(32) and beyond from Andrew Howroyd, Oct 02 2017

Status

approved