A wasteful number is a positive integer whose decimal prime
factorization uses more digits than the decimal representation
of , counting the digits of the
prime factors and of exponents
greater than 1, but not multiplication signs (Pinch 1998, p. 1). The first few
wasteful numbers are 4, 6, 8, 9, 12, 18, 20, 22, 24, ... (OEIS A046760).
Pinch, R. G. E. "Economical Numbers." 9 Feb 1998. https://arxiv.org/abs/math/9802046.Rivera,
C. "Problems & Puzzles: Puzzle 053-Sequences of Consecutive Economical Numbers."
https://www.primepuzzles.net/puzzles/puzz_053.htm.Santos,
B. R. "Problem 2204. Equidigital Representation." J. Recr. Math.27,
58-59, 1995.Sloane, N. J. A. Sequence A046760
in "The On-Line Encyclopedia of Integer Sequences."
whose decimal prime
factorization uses more digits than the decimal representation
of 
, counting the digits of the
prime factors and of exponents
greater than 1, but not multiplication signs (Pinch 1998, p. 1). The first few
wasteful numbers are 4, 6, 8, 9, 12, 18, 20, 22, 24, ... (OEIS A046760).
, a number that is not wasteful is either an equidigital number or an economical
number.
