OFFSET
1,6
LINKS
John Mason, Table of T(n,k) for n <= 18 (n <= 17 from R. J. Mathar)
Andrew Clarke, Isoperimetrical Polyominoes
John Mason, Incomplete rows for n>18
FORMULA
A131487(e) = Sum_{e=2*n+p} T(n,p).
EXAMPLE
The triangle has rows n=1,2,3,... and columns p=2,3,4,5,...:
1;
0, 1;
0, 0, 2;
0, 0, 1, 4;
0, 0, 0, 1, 11;
0, 0, 0, 1, 7, 27;
0, 0, 0, 0, 4, 21, 83;
0, 0, 0, 0, 2, 21, 91, 255;
0, 0, 0, 0, 1, 9, 89, 339, 847;
0, 0, 0, 0, 0, 6, 67, 393, 1360, 2829;
0, 0, 0, 0, 0, 1, 45, 325, 1713, 5255, 9734;
...
CROSSREFS
KEYWORD
AUTHOR
R. J. Mathar, Mar 07 2021
STATUS
approved