A359689 a(n) is the number of free polyiamonds of n cells with chessboard coloring.
2, 1, 2, 4, 8, 19, 48, 120, 320, 864, 2372, 6581, 18470, 52094, 147966, 421931, 1208214, 3470789, 10001186, 28892674, 83671476, 242823392, 706090582, 2056861981, 6001601254, 17538308071, 51323923796, 150389970179, 441211039118, 1295886198194, 3810209524640, 11214075937205, 33035791339150
Offset: 1
Keywords
Links
- John Mason, Table of n, a(n) for n = 1..51
- John Mason, Counting Polyiamonds
- John Mason, Illustrations
Formula
See link "Counting Polyiamonds".
Extensions
More terms from John Mason, Oct 28 2023