Pell-Lucas numbers: numerators of continued fraction convergents to sqrt(2).

Terms

a(0) =1a(1) =1a(2) =3a(3) =7a(4) =17a(5) =41a(6) =99a(7) =239a(8) =577a(9) =1393a(10) =3363a(11) =8119a(12) =19601a(13) =47321a(14) =114243a(15) =275807a(16) =665857a(17) =1607521a(18) =3880899a(19) =9369319a(20) =22619537a(21) =54608393a(22) =131836323a(23) =318281039a(24) =768398401a(25) =1855077841a(26) =4478554083a(27) =10812186007a(28) =26102926097a(29) =63018038201