-1101

Appears in sequences

• sech(arctan(tanh(x)))=1-1/2!*x^2+21/4!*x^4-1101/6!*x^6+109001/8!*x^8...at n=3A012230
• Triangle T(n,k), read by rows, formed by setting all entries in the zeroth column and in the main diagonal ((n,n) entries) to 1 and defining the rest of the entries by the recursion T(n,k) = T(n-1,k) - T(n,k-1).at n=52A096470
• Expansion of exp( Sum_{n>=1} -sigma_2(2*n)*x^n/n ) in powers of x.at n=14A283242