-1276

Appears in sequences

• n times the coefficient of x^n in log[1 + sum(k>=0, x^2^k)].at n=39A092462
• The trinomial transform (A027907) gives powers of 2, while the trinomial transform of this sequence shift one place left gives powers of 3.at n=12A100321
• Expansion of -(7*x^2+3*x-1)*(2*x^2+2*x+1) / ((3*x^2+3*x+1)*(2*x^3+2*x^2+4*x+1)).at n=5A110687
• Semiprime(n)*semiprime(n+3) - semiprime(n+1)*semiprime(n+2), where semiprime(n) is the n-th semiprime.at n=49A118780
• a(n) = a(n-2) - (a(n-1) - a(n-2)) if (n mod 2) = 0, otherwise a(n) = a(n-1) - (a(n-3) - a(n-4)), with a(0) = 0, a(1) = 1, a(2) = -1, a(3) = 2.at n=34A135690
• G.f. satisfies: A(x) = A(x^2 - x^3)/(1-x).at n=25A251659
• First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 6", based on the 5-celled von Neumann neighborhood.at n=31A269698
• First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 605", based on the 5-celled von Neumann neighborhood.at n=43A273178
• First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 662", based on the 5-celled von Neumann neighborhood.at n=37A273391
• Expansion of 1/(1 - x/(1 + x/(1 + x^2/(1 + x^3/(1 + x^4/(1 + x^5/(1 + ...))))))), a continued fraction.at n=67A302015
• a(n) = Sum_{d|n} mu(d) * binomial(d+n/d-1, d).at n=49A338657