'Geobonnaci' sequence: a(1)=a(2)=1, thereafter a(n) = round( 2 * sqrt(a(n-1) * a(n-2)) ).

Terms

a(0) =1a(1) =1a(2) =2a(3) =3a(4) =5a(5) =8a(6) =13a(7) =20a(8) =32a(9) =51a(10) =81a(11) =129a(12) =204a(13) =324a(14) =514a(15) =816a(16) =1295a(17) =2056a(18) =3263a(19) =5180a(20) =8222a(21) =13052a(22) =20718a(23) =32888a(24) =52206a(25) =82872a(26) =131551a(27) =208824a(28) =331488a(29) =526204