28130

Appears in sequences

• Number of 3-element antichains on an unlabeled n-element set; equivalence classes of monotone Boolean functions of n variables with 3 mincuts under action of symmetric group S_n.at n=16A056778
• a(n) = 625n^2 - 364n + 53.at n=6A157621
• Triangle read by rows: Take a pentagon with all diagonals drawn, as in A331929. Then T(n,k) = number of k-sided polygons in that figure for k = 3, 4, ..., n+5.at n=50A331939
• Numbers k such that the equation x^2 - k*y^4 = -1 has a solution for which |y| > 2.at n=18A356488
• Number of growing self-avoiding walks with displacement n on a half-infinite strip of height 5 with a trapped endpoint.at n=3A374302
• Number of subsets of {1,2,...,n} such that no two elements differ by 1 or 5.at n=24A374737
• Integers k such that there exists an integer 0<m<k such that sigma(m)^2 + sigma(k)^2 = 2*(m+k)^2.at n=13A385008