262372domain: NAppears in sequencesSum_{d|n, d odd} d*2^(n/d).at n=18A054600Number of (n+1)X(1+1) 0..1 arrays x(i,j) with row sums sum{x(i,j), j=1..1+1} nondecreasing, and column sums sum{i^2*x(i,j), i=1..n+1} nondecreasing.at n=15A233297a(n) = Sum_{k=1..n} (-2)^(floor(n/k) - 1).at n=18A345034