30408704

Appears in sequences

• First differences of A045891.at n=24A034007
• Number of subsets of {2,...,n} such that the product of their elements is congruent to 0 (mod n+1).at n=24A064381
• Second differences of A045623, prefixed by an initial 1.at n=23A109975
• a(n) = (3*n+1)*2^n.at n=19A130129
• Number of ascending runs in {1,...,4}^n.at n=11A229278
• G.f. satisfies: A(x) = exp( Sum_{n>=1} [Sum_{k=0..2*n} T(n,k)^2 * x^k] / A(x)^n * x^n/n ), where T(n,k) is the coefficient of x^k in (1 + x + 2*x^2)^n.at n=41A251687
• a(n) = A257851(n,n).at n=19A264959
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 478", based on the 5-celled von Neumann neighborhood.at n=31A288506
• Consider the Post tag system defined in A284116; a(n) = number of binary words of length n which terminate at the empty word.at n=26A289670