8155591domain: NPropertiesPrimalityPrimeyesAppears in sequencesa(n) = (n/3 + 7/9)*2^(n - 1) + (-1)^n/9.at n=20A127984Expansion of 1 / ( (1+x)*(2*x+1)*(-1+2*x)^2 ).at n=20A140787Prime numbersat n=549519