A115982 Number of planar partitions that are not corners.

0, 0, 0, 1, 3, 10, 23, 54, 112, 228, 437, 826, 1499, 2685, 4688, 8079, 13668, 22875, 37738, 61676, 99672, 159742, 253681, 399962, 625741, 972756, 1502302, 2306988, 3522492, 5351239, 8088469, 12170163, 18229411, 27192571

Offset: 1

Author

Alford Arnold, Feb 17 2006

Keywords

• easy
• nonn

Comments

a(n) can also be approximated by considering A000094 since A000094(n) = A000041(n) - n = 0 0 0 1 2 5 8 14 21 32 ... with partial sums 0 0 0 1 3 8 16 30 51 83 ... which counts many of the initial cases. The remaining cases form 0 0 0 0 0 2 7 24 ... counting for n=6, 22/11 and 21/21.

Examples

			The planar partitions begin 1 3 6 13 24 48 ... A000219 with corners 1 3 6 12 21 38 ... A006330; therefore the present sequence begins 0 0 0 1 3 10 ...
		

Crossrefs

Cf. A000219, A006330, A000041, A000094.

Formula

a(n) = A000219(n) - A006330(n)

Extensions

Edited with additional terms by Franklin T. Adams-Watters, Mar 10 2006