a(n+1) is the integer part of sqrt(2*a(n)^2).

Terms

a(0) =3a(1) =4a(2) =5a(3) =7a(4) =9a(5) =12a(6) =16a(7) =22a(8) =31a(9) =43a(10) =60a(11) =84a(12) =118a(13) =166a(14) =234a(15) =330a(16) =466a(17) =659a(18) =931a(19) =1316a(20) =1861a(21) =2631a(22) =3720a(23) =5260a(24) =7438a(25) =10518a(26) =14874a(27) =21035a(28) =29747a(29) =42068