-381

Appears in sequences

• Expansion of x^2*(-1+x+x^2)/(-1+x+x^2-x^3+x^5).at n=23A107332
• Riordan array (1/(1+xc(-2x)), xc(-2x)/(1+xc(-2x))), c(x) the g.f. of A000108.at n=15A114189
• Expansion of 1/(1+x*c(-2*x)), c(x) the g.f. of A000108.at n=5A114191
• Numerators of Blandin-Diaz compositional Bernoulli numbers (B^sin)_3,n.at n=5A132092
• Numerator of Bernoulli(n, 1/10).at n=5A158992
• Expansion of 1 - 3*(1-x-sqrt(1-2*x-3*x^2))/2.at n=9A168076
• Values of n such that L(11) and N(11) are both prime, where L(k) = (n^2+n+1)*2^(2*k) + (2*n+1)*2^k + 1, N(k) = (n^2+n+1)*2^k + n.at n=9A227449
• Triangle read by rows: T(n,k) is the coefficient A_k in the transformation Sum_{k=0..n} (k+1)*x^k = Sum_{k=0..n} A_k*(x+2)^k.at n=17A246788
• Expansion of f(-x) * f(x^4, x^8) / f(-x^3)^2 in powers of x where f(, ) is Ramanujan's general theta function.at n=43A263050
• Let f(x) = 1 -x^3+ Sum_{j>=2} (x^(2^j)-x^(1+2^j)). Then a(n) is n times the coefficient of x^n in the expansion of log(f(x)).at n=27A271726
• Dirichlet g.f.: 1 / (zeta(s) * zeta(s-1) * zeta(s-2)).at n=18A328254
• a(1)=0; thereafter a(n) = (n-1)*sigma(n)-n*sigma(n-1) where sigma is the sum-of-divisors function A000203.at n=18A335153
• For 1<=x<=n, 1<=y<=n, with gcd(x,y)=1, write 1 = gcd(x,y) = u*x+v*y with u,v minimal; a(n) = sum of the values of u+v.at n=51A345425
• Sum of A250469 and its Dirichlet inverse.at n=59A346480
• G.f. A(x,y) = Sum_{n>=0} x^n/(1-y)^(2*n+1) * Sum_{k=0..3*n} T(n,k)*y^k satisfies: y = Sum_{n=-oo..+oo} (-1)^n * x^(n*(n+1)/2) * A(x,y)^n.at n=53A355870
• a(0) = 0; for n >= 1, a(n) = -(3/2)*(a(n-1)+A355905(n-1)).at n=14A355906
• Expansion of Product_{k>=1} 1 / (1 + x^Fibonacci(k)).at n=35A357381
• Quotient (A003961(k)-sigma(k)) / (2*k-A003961(k)) computed for those k for which this quotient is an integer, where A003961 is fully multiplicative with a(prime(i)) = prime(i+1).at n=19A379217