a(n) = (n+1)*(2^n+1) for n > 0 with a(0)=1.

Terms

a(0) =1a(1) =6a(2) =15a(3) =36a(4) =85a(5) =198a(6) =455a(7) =1032a(8) =2313a(9) =5130a(10) =11275a(11) =24588a(12) =53261a(13) =114702a(14) =245775a(15) =524304a(16) =1114129a(17) =2359314a(18) =4980755a(19) =10485780a(20) =22020117a(21) =46137366a(22) =96469015a(23) =201326616a(24) =419430425a(25) =872415258a(26) =1811939355a(27) =3758096412