536870970domain: NAppears in sequencesa(0)=0; for n>0, a(n) = Sum_{d|n} d*2^(n/d).at n=29A054598Sum_{d|n, d odd} d*2^(n/d).at n=29A054600Number of 2 X n 0-1 matrices avoiding simultaneously the right angled numbered polyomino patterns (ranpp) (00;1), (01;0), (10;0) and (01;1).at n=29A100314