26768

Appears in sequences

• Expansion of e.g.f.: cosh(arcsin(x)*log(x+1)).at n=8A012313
• Expansion of e.g.f. sec(arcsinh(x)*arctan(x)) (only even powers).at n=4A012632
• arcsinh(exp(x)-cos(x))=x+2/2!*x^2-12/4!*x^4-60/5!*x^5+32/6!*x^6...at n=7A013316
• a(1)=4, a(2)=2, a(n) = 4*a(n-1) + 2*a(n-2).at n=7A189741
• Composite numbers whose sum of aliquot parts divides the sum of the aliquot parts of the numbers less than or equal to n and not relatively prime to n.at n=22A249109
• a(n) is the largest integer k such that sigma(k)/(d(k)*sopf(k)) = n where d=A000005, sigma=A000203 and sopf=A008472.at n=11A328175
• G.f. A(x) satisfies: A(x) = (1 - x*A(x)) * Sum_{n>=0} x^n / (1 - x*A(x)^(2*n+1)).at n=9A340893
• a(n) = Sum_{k=0..floor(3*n/14)} binomial(3*n-13*k,k).at n=26A392351