31998903

Appears in sequences

• Number of connected permutations of [1..n] (those not fixing [1..j] for 0 < j < n). Also called indecomposable permutations, or irreducible permutations.at n=11A003319
• G.f. A(x) satisfies: [x^n] A(x)^n = [x^n] A(x)^(n-1) for n>1 with A(0)=A'(0)=1.at n=11A158882
• A recurrent sequence in Panaitopol's formula for pi(x), where pi(x) is the number of primes <= x.at n=10A233824
• Bisection of A003319: a(n) = A003319(2n+1).at n=5A272657
• Array read by downward antidiagonals: A(n,k) = (k+2)*A(n-1,k+1) + Sum_{j=0..k} A(n-1,j) with A(0,k) = 1, n >= 0, k >= 0.at n=54A370380
• Array read by downward antidiagonals: A(n,k) = Sum_{j=0..k+1} binomial(k+2, j+1)*A(n-1,j) with A(0,k) = 1, n >= 0, k >= 0.at n=54A370381