262298domain: NAppears in sequencesSemiprimes in A103378.at n=27A103398Number of involutions avoiding the pattern 2431.at n=14A230551G.f. A(x) satisfies: Sum_{n>=0} x^n*A(x)^(n*(n+1)/2) = Sum_{n>=0} x^n*(1+x)^(n^2).at n=10A325289Number of compositions (ordered partitions) of n into distinct parts, the least being 1.at n=37A339162