100663320domain: NAppears in sequencesa(0)=1, a(1)=2; for n>1, a(n) = n*(2^n+4)/4.at n=24A227978n * (2 + 2^(2*n - 1)).at n=12A229135a(n) = 3*2^n + n - 1.at n=25A275970