A nialpdrome is a number whose hexadecimal digits are in nonincreasing order. The first few are 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 32, 33, 34, 48, 49, 50, ... (OEIS A023771), corresponding to 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F, 10, 11, 20, 21, 22, 30, 31, 32, .... A number that is not a nialpdrome is a metadrome. The following table summarized related classes of numbers. name | base-16 digit order katadrome | strict descending metadrome | strict ascending nialpdrome | nonincreasing plaindrome | nondecreasing

digit | hexadecimal | katadrome | metadrome | plaindrome