A227940 Number of runs of strictly increasing numbers of 2 X 2 squares in the list of partitions of n^2 into squares, where partition sorting order is ascending with larger squares taking higher precedence.
1, 1, 2, 3, 6, 12, 20, 42, 84, 171, 327, 654, 1288, 2533, 4942, 9566, 18481, 35449, 67649, 128372, 242451, 455393, 851352, 1583854, 2932250, 5403874, 9913868, 18107914, 32932025, 59643292
Offset: 1
Keywords
Examples
For n = 4, the 8 partitions of 16 into square parts are: Partition Square side . 1 2 3 4 . . 1 16 0 0 0 . 2 12 1 0 0 . 3 8 2 0 0 . 4 4 3 0 0 . 5 0 4 0 0 . 6 7 0 1 0 . 7 3 1 1 0 . 8 0 0 0 1 So a(4) = 3 as there are 3 runs of 2 X 2 squares: (0,1,2,3,4) from partitions 1 to 5, (0,1) from partitions 6 to 7 and (0) from partition 8.
Links
- Christopher Hunt Gribble, C++ program
Crossrefs
Cf. A037444.