@ARTICLE{NUMBER06.MIZ,
  AUTHOR = {Grabowski, Adam},
  TITLE = {Elementary Number Theory Problems. {P}art {VI}},
  SECTION1 = {Preliminaries},
  SECTION2 = {Arithmetic Progressions},
  SECTION3 = {Problem 50},
  SECTION4 = {Triangular Numbers},
  SECTION5 = {Problem 54},
  SECTION6 = {Problem 55},
  SECTION7 = {Problem 56},
  SECTION8 = {Problem 60},
  SECTION9 = {Problem 64},
  SECTION10 = {Problem 70},
  SECTION11 = {Problem 71},
  SECTION12 = {Problem 73},
  DAY = {30},
  MONTH = {September},
  YEAR = {2022},
  ADDRESS1 = {Institute of Computer Science\\University of Bia{\l}ystok\\ Konstantego Cio{\l}kowskiego 1M, 15-245 Bia{\l}ystok\\Poland},
  SUMMARY = {This paper reports on the formalization of ten selected problems from
  W. Sierpinski's book ``250 Problems in Elementary Number Theory'' \cite{Sierpinski:1970}.
  This article is devoted mainly to arithmetic progressions:
  problems 52, 54, 55, 56, 60, 64, 70, 71, and 73 belong to the chapter ``Arithmetic Progressions'', and problem 50 is from ``Relatively Prime Numbers''.}}
