a(n) = p*(p+(2n-1))/2, where p = A096822(n) is the smallest primes of form 2^x-(2n-1).

Terms

a(0) =6a(1) =20a(2) =12a(4) =56a(5) =40a(6) =24a(7) =272a(8) =1504a(9) =208a(10) =176a(11) =1312a(12) =112a(13) =80a(14) =48a(15) =6208a(16) =992a(17) =928a(18) =2059264a(19) =5696a(20) =736a(22) =608a(23) =544a(24) =5056a(25) =416a(26) =352a(27) =4672a(28) =224a(29) =160a(30) =96a(31) =24704