Smith brothers are consecutive Smith numbers. The first few Smith brothers are (728, 729), (2964, 2965), (3864, 3865), (4959, 4960), ... (OEIS A050219 and A050220).
Smith Brothers
See also
Smith NumberExplore with Wolfram|Alpha
References
Sloane, N. J. A. Sequences A050219 and A050220 in "The On-Line Encyclopedia of Integer Sequences."Referenced on Wolfram|Alpha
Smith BrothersCite this as:
Weisstein, Eric W. "Smith Brothers." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/SmithBrothers.html