Numbers whose base-4 representation contains exactly four 1's and two 2's.

Terms

a(0) =1370a(1) =1382a(2) =1385a(3) =1430a(4) =1433a(5) =1445a(6) =1622a(7) =1625a(8) =1637a(9) =1685a(10) =2390a(11) =2393a(12) =2405a(13) =2453a(14) =2645a(15) =4442a(16) =4454a(17) =4457a(18) =4502a(19) =4505a(20) =4517a(21) =4694a(22) =4697a(23) =4709a(24) =4757a(25) =5210a(26) =5222a(27) =5225a(28) =5270a(29) =5273