OFFSET
2,1
COMMENTS
Number of ways to place 2k*(n-k) nonattacking ferses on a 2k X (2n-2k) board. - Tricia Muldoon Brown, Dec 12 2018
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 2..5461
Tricia Muldoon Brown, The Problem of Pawns, arXiv:1811.09606 [math.CO], 2018.
FORMULA
a(n) = A014410(n)^2. - Sean A. Irvine, Nov 18 2018
EXAMPLE
Triangle begins:
4,
9, 9,
16, 36, 16,
25, 100, 100, 25,
36, 225, 400, 225, 36,
...
MAPLE
T:=(n, k)->binomial(n, k)^2: seq(seq(T(n, k), k=1..n-1), n=2..11); # Muniru A Asiru, Dec 12 2018
MATHEMATICA
Select[Flatten[Table[Binomial[n, i]^2, {n, 0, 25}, {i, 0, n}]], #>1 &] (* Vincenzo Librandi, Nov 19 2018 *)
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
EXTENSIONS
More terms from Sean A. Irvine, Nov 18 2018
Offset corrected by Joerg Arndt, Nov 19 2018
STATUS
approved