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A392995
Number of plane partitions with multiplicities of parts matching the n-th composition in standard order.
9
1, 2, 2, 3, 4, 3, 4, 5, 7, 8, 10, 5, 7, 8, 10, 7, 12, 13, 18, 12, 20, 18, 26, 7, 12, 13, 18, 12, 20, 18, 26, 11, 19, 25, 34, 23, 37, 37, 52, 20, 34, 42, 58, 32, 52, 54, 76, 11, 19, 25, 34, 23, 37, 37, 52, 20, 34, 42, 58, 32, 52, 54, 76, 15, 30, 39, 56, 42, 72
OFFSET
1,2
COMMENTS
a(n) is the number of normal generalized Young tableaux with rows and columns weakly decreasing (Cf. A299926), whose entries have multiplicities matching the n-th composition in standard order.
LINKS
John Tyler Rascoe, Python code.
FORMULA
a(2^k + j) = a(2^k + j + 2^(k-1)) for k > 0 and 0 <= j < 2^(k-1) - 1.
a(2^k-1) = A000085(k) for k > 0.
a(2^k) = A000041(k+1).
a(2^k+1) = A000070(k).
EXAMPLE
The 5th composition in standard order (2,1) corresponds to plane partitions with 3 parts (a^2,b), so a(5) = 4:
a a b a a a b a
b a a
b
PROG
(Python) # see links
KEYWORD
nonn
AUTHOR
John Tyler Rascoe, Jan 29 2026
STATUS
approved