Tiara number triangles

Studies of Boolean functions
sequences related to Boolean functions
tiara as jewellery

A tiara is a number triangle whose entries for row correspond to the weight of an -ary Boolean function.
The weight is often shown as an integer , but it is essentially a fraction .     E.g. balanced BF have weight , and the tautology has weight 1.

The column index can also represent the nonlinearity of a BF. This leads to the unusual tiara Amber, with non-zero enries only in the left half.

An important property of a tiara is the regular triangle of unit fractions, which shall be called its slab. They are shown in the boxes below. See also the example for Emerald.
It is not usually an otherwise known triangle, but for Ruby it is ExPascal, and for Opal it is A289537 with row sums A182176 (number of affine subspaces of F2n.)

The names of tiaras and other sequences in this article are likely to be changed again.

The most obvious tiara is that of all Boolean functions. Row is row of Pascal's triangle, and the row sums are . In the triangle of unit fractions .

tiara Clay    row sums Grass (A001146)
rational weight
w
a
sums
0

1

1 2
1

1

2 1 4
2

1

4 6 4 1 16
3

1

8 28 56 70 56 28 8 1 256
4

1

16 120 560 1820 4368 8008 11440 12870 11440 8008 4368 1820 560 120 16 1 65536
5

1

32 496 4960 35960 201376 906192 3365856 10518300 28048800 64512240 129024480 225792840 347373600 471435600 565722720 601080390 565722720 471435600 347373600 225792840 129024480 64512240 28048800 10518300 3365856 906192 201376 35960 4960 496 32 1 4294967296

An important subset are the dense BF, usually called non-degenerate:

equivalence classes

numbers of families

The central column in Saffron.

numbers of diploid families

is the number of -subsets of whose bitwise XOR is 0.     The row sums are .
E.g. T(4, 3) = 35 is the number of 3-subsets of 0...15 whose bitwise XOR is 0.
Those are:   (1, 2, 3), (1, 4, 5), (1, 6, 7), (1, 8, 9), (1, 10, 11), (1, 12, 13), (1, 14, 15), (2, 4, 6), (2, 5, 7), (2, 8, 10), (2, 9, 11), (2, 12, 14), (2, 13, 15), (3, 4, 7), (3, 5, 6), (3, 8, 11), (3, 9, 10), (3, 12, 15), (3, 13, 14), (4, 8, 12), (4, 9, 13), (4, 10, 14), (4, 11, 15), (5, 8, 13), (5, 9, 12), (5, 10, 15), (5, 11, 14), (6, 8, 14), (6, 9, 15), (6, 10, 12), (6, 11, 13), (7, 8, 15), (7, 9, 14), (7, 10, 13), (7, 11, 12)
The central column is A340259.

numbers of clans

The central column is A000721.

numbers of factions

oddacity and gender

Gender of Boolean functions § oddacity and gender

0 1 2 3 4
female 1 1 3 97 32199
evenacious female 1 1 1 57 30537
oddacious female 0 0 2 40 1662
oddacious male 1 3 13 159 33337
oddacious 1 3 15 199 34999
all 2 4 16 256 65536

mentor permutation

These tiaras count the fixed points of the mentor permutation. (Both have the same row sums.)
Flint is for the permutation between Zhegalkin indices, and Slate for the one between truth tables. The latter is symmetric.