A274597 Number of ways to remove n oranges from an infinite stack of oranges whose m-th layer is an m X (m+3) rectangle.

1, 4, 10, 28, 68, 158, 350, 750, 1559, 3170, 6292, 12252, 23445, 44164, 81995, 150288, 272150, 487388, 863887, 1516592, 2638648, 4552488, 7792566, 13239698, 22336630, 37433466, 62337628, 103186612, 169824540, 277967860, 452594316, 733229626, 1182159039, 1897140990, 3031012912

Offset: 0

Author

Suresh Govindarajan, Jun 30 2016

Keywords

• nonn
• hard

Comments

This problem was stated in this fashion by R. Kenyon and Ben Young in the Domino Forum ([e-mail]).

Links

• Suresh Govindarajan, Table of n, a(n) for n = 0..45
• Domino Forum, Domino Home Page
• S. Govindarajan, A. J. Guttmann and V. Subramanyan, On a square-ice analogue of plane partitions, arXiv:1607.01890 [cond-mat.stat-mech], 2016.

Crossrefs

Cf. A274582, A274594, A274596, A274598, A274599.