31992

Appears in sequences

• T(n,n-3), array T as in A047120.at n=8A047125
• a(n) is the number of nonsymmetric patterns (no reflective, nor rotational symmetry) which may be formed by an equilateral triangular arrangement of closely packed black and white cells satisfying the local matching rule of Pascal's triangle modulo 2, where n is the number of cells in each edge of the arrangement. The matching rule is such that any elementary top-down triangle of three neighboring cells in the arrangement contains either one or three white cells.at n=14A060551
• Triangle T(m,k) read by rows, where T(m,k) is the number of ways in which 1 <= k <= m positions can be picked in an m X m square array such that their adjacency graph consists of a single component. Two positions (s,t), (u,v) are considered as adjacent if max(abs(s-u), abs(t-v)) <= 1.at n=20A098485
• a(n) = (2*n^3 + 5*n^2 - 13*n)/2.at n=30A162262
• The number of right-crucial (with respect to squares) permutations of 1,...,n.at n=11A221990
• Number of partitions p of n such that max(p) - 2*min(p) is a part of p.at n=47A238626
• a(n) = phi(6^n-1)/n, where phi is Euler's totient function (A000010).at n=6A295496
• Number of free pure symmetric multifunctions with one atom, n positions, and no empty or unitary parts (subexpressions of the form x[] or x[y]).at n=21A303027
• a(n) is the hafnian of the 2n X 2n symmetric matrix defined by M[i,j] = floor(i*j/3).at n=4A358158
• Array read by antidiagonals: T(n,k) = phi(k^n-1)/n, where phi is Euler's totient function (A000010), n >= 1, k >= 2.at n=61A369291