Expansion of Sum_{n>=1} ( (2 + x^n)^n - 2^n ).

Terms

a(0) =1a(1) =4a(2) =12a(3) =33a(4) =80a(5) =198a(6) =448a(7) =1048a(8) =2305a(9) =5200a(10) =11264a(11) =24824a(12) =53248a(13) =115360a(14) =245800a(15) =526081a(16) =1114112a(17) =2364064a(18) =4980736a(19) =10497290a(20) =22020656a(21) =46165504a(22) =96468992a(23) =201396028a(24) =419430401a(25) =872574976a(26) =1811944704a(27) =3758469400a(28) =7784628224a(29) =16107002892