Numbers that are multiples of 28 and contain both a 4 and a 7.

Terms

a(0) =476a(1) =784a(2) =1764a(3) =2744a(4) =3472a(5) =3724a(6) =4172a(7) =4676a(8) =4704a(9) =4732a(10) =4760a(11) =4788a(12) =4872a(13) =5740a(14) =6748a(15) =7084a(16) =7140a(17) =7224a(18) =7364a(19) =7420a(20) =7448a(21) =7476a(22) =7504a(23) =7644a(24) =7784a(25) =7840a(26) =7924a(27) =8764a(28) =9744a(29) =10472