A133264 Smallest number whose sum of digits is 3n+1.

1, 4, 7, 19, 49, 79, 199, 499, 799, 1999, 4999, 7999, 19999, 49999, 79999, 199999, 499999, 799999, 1999999, 4999999, 7999999, 19999999, 49999999, 79999999, 199999999, 499999999, 799999999, 1999999999, 4999999999, 7999999999