Interleave denominators (A000129) and numerators (A001333) of convergents to sqrt(2).

Terms

a(0) =0a(1) =1a(2) =1a(3) =1a(4) =2a(5) =3a(6) =5a(7) =7a(8) =12a(9) =17a(10) =29a(11) =41a(12) =70a(13) =99a(14) =169a(15) =239a(16) =408a(17) =577a(18) =985a(19) =1393a(20) =2378a(21) =3363a(22) =5741a(23) =8119a(24) =13860a(25) =19601a(26) =33461a(27) =47321a(28) =80782a(29) =114243