Column 2 of the array m(i,1)=m(1,j)=1 m(i,j)=m(i-1,j-1)+m(i-1,j+1) (a(n)=m(n,2)).

Terms

a(0) =1a(1) =2a(2) =3a(3) =5a(4) =8a(5) =14a(6) =24a(7) =44a(8) =79a(9) =149a(10) =275a(11) =527a(12) =989a(13) =1913a(14) =3629a(15) =7061a(16) =13496a(17) =26366a(18) =50676a(19) =99296a(20) =191674a(21) =376430a(22) =729146a(23) =1434578a(24) =2786656a(25) =5490812a(26) =10691112a(27) =21091712a(28) =41150012a(29) =81266612