a(n)^4 is smallest fourth power beginning with n.

Terms

a(0) =0a(1) =1a(2) =4a(3) =14a(4) =8a(5) =15a(6) =5a(7) =29a(8) =3a(9) =31a(10) =10a(11) =33a(12) =6a(13) =19a(14) =11a(15) =35a(16) =2a(17) =65a(18) =37a(19) =21a(20) =12a(21) =68a(22) =69a(23) =22a(24) =7a(25) =4a(26) =72a(27) =23a(28) =13a(29) =74