Overlay of Pell companion numbers: a(n) = A001333(n) + A001333(n-6).

Terms

a(0) =1a(1) =1a(2) =3a(3) =7a(4) =17a(5) =41a(6) =100a(7) =240a(8) =580a(9) =1400a(10) =3380a(11) =8160a(12) =19700a(13) =47560a(14) =114820a(15) =277200a(16) =669220a(17) =1615640a(18) =3900500a(19) =9416640a(20) =22733780a(21) =54884200a(22) =132502180a(23) =319888560a(24) =772279300a(25) =1864447160a(26) =4501173620a(27) =10866794400a(28) =26234762420a(29) =63336319240