Number of integers <= 2^n of form x^2 - 2y^2.

Terms

a(0) =1a(1) =2a(2) =3a(3) =5a(4) =8a(5) =15a(6) =26a(7) =48a(8) =87a(9) =161a(10) =299a(11) =563a(12) =1066a(13) =2030a(14) =3885a(15) =7464a(16) =14384a(17) =27779a(18) =53782a(19) =104359a(20) =202838a(21) =394860a(22) =769777a(23) =1502603a(24) =2936519a(25) =5744932a(26) =11249805a(27) =22048769a(28) =43248623a(29) =84894767