A014719 Squares of elements in Pascal triangle (by row) that are not 1.

4, 9, 9, 16, 36, 16, 25, 100, 100, 25, 36, 225, 400, 225, 36, 49, 441, 1225, 1225, 441, 49, 64, 784, 3136, 4900, 3136, 784, 64, 81, 1296, 7056, 15876, 15876, 7056, 1296, 81, 100, 2025, 14400, 44100, 63504, 44100, 14400, 2025, 100, 121, 3025

Offset: 2

Author

Mohammad K. Azarian

Keywords

• nonn
• tabl

Comments

Number of ways to place 2k*(n-k) nonattacking ferses on a 2k X (2n-2k) board. - Tricia Muldoon Brown, Dec 12 2018

Examples

			Triangle begins:
  4,
  9, 9,
  16, 36, 16,
  25, 100, 100, 25,
  36, 225, 400, 225, 36,
  ...
		

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.

Crossrefs

Cf. A007318, A014410.

Programs

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 *)

Formula

a(n) = A014410(n)^2. - Sean A. Irvine, Nov 18 2018

Extensions

More terms from Sean A. Irvine, Nov 18 2018

Offset corrected by Joerg Arndt, Nov 19 2018