24549

Appears in sequences

• Numbers k such that 3*R_k - 2 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=27A055557
• a(n) = (2*n-1)*(5*n^2-5*n+6)/6.at n=24A063489
• A symmetrical triangle of coefficients of polynomials: q(x,n)=((1 - x)^(2*n)/(n*x))*Sum[Binomial[k + n - 1, k]*k^n*x^k, {k, 0, Infinity}]; p(x,n)=q(x,n)+x^(n-1)*q(1/x,n); t(n,m)=coefficients(p(x,n)).at n=16A152300
• A symmetrical triangle of coefficients of polynomials: q(x,n)=((1 - x)^(2*n)/(n*x))*Sum[Binomial[k + n - 1, k]*k^n*x^k, {k, 0, Infinity}]; p(x,n)=q(x,n)+x^(n-1)*q(1/x,n); t(n,m)=coefficients(p(x,n)).at n=19A152300
• a(n) = 68*n^2 + 1.at n=19A158732
• Denominators of the convergents given by treating A390946 as continued fraction coefficients after the leading 0.at n=12A391907