A274598 Number of ways to remove n oranges from an infinite stack of oranges whose m-th layer is an m X (m+4) rectangle.

1, 5, 14, 40, 103, 247, 567, 1252, 2668, 5539, 11214, 22247, 43300, 82871, 156152, 290202, 532430, 965395, 1731351, 3073660, 5404984, 9420512, 16282463, 27922063, 47527430, 80331385, 134873275, 225015223, 373141724, 615224276, 1008792896, 1645443771, 2670372299, 4312780664, 6933014899

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, A274597, A274599.