90246

Appears in sequences

• E.g.f.: exp( Sum_{n>=1} x^n * Sum_{k=1..n} 1/k^2 ) = Sum_{n>=0} a(n)*x^n/n!^2.at n=5A182529
• Number of subsets of {1,...,n} containing {a,a+2,a+4} for some a.at n=17A209409
• G.f.: 1 + Sum_{n>=1} a(n)*x^n/(1 - x^n) = Product_{n>=1} (1 + x^n)/(1 - x^n).at n=28A300274
• a(n) = [x^n] Product_{k>=1} (1 + x^k)*(1 - x^(n*k))/((1 - x^k)*(1 + x^(n*k))).at n=29A304627