32663

Appears in sequences

• a(n) = 2^n - n*(n-1)/2.at n=15A014844
• Leading diagonal of triangle in A080521.at n=14A080522
• Semiprimes in A103379.at n=20A103399
• Numerators in the resistance triangle: T(k,n)=b, where b/c is the resistance distance R(k,n) for k resistors in an n-dimensional cube.at n=34A212045
• Triangle read by rows: T(n,k) = number of topologies on an n-set X such that there are exactly k elements in X that are topologically distinguishable, n >= 0, 0 <= k <= n.at n=36A280192
• Number of topologies on an n-set X such that for all x in X there is a y in X such that x and y are topologically indistinguishable.at n=8A280202
• a(n) = numerator(-1/n + Sum_{k=1..n} 2^(k-1)/k).at n=7A332786
• Expansion of Product_{k>=1} (1 + x^k * (1 + k*x)).at n=23A336980
• Triangular array read by rows. T(n,k) is the number of labeled transitive relations on [n] that have exactly k symmetric points.at n=44A355783