-3340

Appears in sequences

• Array: row n shows the coefficients of the characteristic polynomial of the n-th principal submatrix of (f(i,j)), where f(i,1)=f(1,j)=1, f(i,i)=2i-1; f(i,j)=0 otherwise; as in A204181.at n=23A204182
• 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=48A335153
• Sum_{n>=0} a(n) * x^n / (n!)^2 = Product_{n>=1} (1 - x^n / (n!)^2).at n=6A346314