54102

Appears in sequences

• G.f. satisfies A(x) = 1 + x*cycle_index(G,A(x)) where G = cyclic group of order 3 generated by (1,2,3)(4,5,6).at n=8A036726
• Number of length 3+2 0..n arrays with the sum of second differences multiplied by some arrangement of +-1 equal to zero.at n=12A250562
• Expansion of Sum_{i>=1} x^(i*(i+1)/2) / (1 - Sum_{j>=1} x^(j*(j+1)/2))^2.at n=20A281810
• a(n) is the largest k such that the sum of k consecutive reciprocals 1/p_n + ... + 1/p_(n+k-1) does not exceed 1 (where p_n = n-th prime).at n=31A327600
• Pseudo-involutory Riordan companion of 1 + 2*x*M(x), where M(x) is the g.f. of A001006.at n=15A348189