89489408domain: NAppears in sequencesa(n) = (2^(n+1) + (-4)^n)/3.at n=14A083086a(n) = - a(n-1) + 5(a(n-2) + a(n-3)) - 2(a(n-4) + a(n-5)) - 8(a(n-6) + a(n-7)).at n=29A090597Expansion of A(x) = Sum_{n>=0} 2^(n*(n-1)/2) * (1 + 2^(2*n+1))/3 * x^(n*(n+1)/2).at n=21A370015