1229220

Appears in sequences

• G.f.: A(x) = INV(x-x^2 - x^2*INV(x-2*x^2 - x^2*INV(x-3*x^2 - x^2*INV(x-4*x^2 - x^2*INV(x-5*x^2 - ...))))), where INV(F(x)) = series reversion of F(x).at n=9A196710
• Number of (n+1)X(1+1) 0..2 arrays x(i,j) with row sums sum{j^2*x(i,j), j=1..1+1} nondecreasing, and column sums sum{i^2*x(i,j), i=1..n+1} nondecreasing.at n=16A232780