Numbers k such that k and k^2 use only the digits 0, 3, 6, 7 and 8.

Terms

a(0) =0a(1) =6a(2) =60a(3) =600a(4) =876a(5) =6000a(6) =8760a(7) =8876a(8) =60000a(9) =87600a(10) =88760a(11) =600000a(12) =876000a(13) =887600a(14) =6000000a(15) =8760000a(16) =8866076a(17) =8876000a(18) =60000000a(19) =60007306a(20) =87600000a(21) =88660760a(22) =88760000a(23) =600000000a(24) =600073060a(25) =600736076a(26) =876000000a(27) =886607600a(28) =887600000a(29) =6000000000