Duplicate of A018240.

Terms

a(0) =1a(1) =1a(2) =2a(3) =3a(4) =7a(5) =12a(6) =24a(7) =45a(8) =91a(9) =176a(10) =352a(11) =693a(12) =1387a(13) =2752a(14) =5504a(15) =10965a(16) =21931a(17) =43776a(18) =87552a(19) =174933a(20) =349867a(21) =699392a(22) =1398784a(23) =2796885a(24) =5593771a(25) =11186176a(26) =22372352a(27) =44741973a(28) =89483947a(29) =178962432