Combinatorial Interpretation of General Eulerian Numbers
  Since 1950s, mathematicians have successfully interpreted the traditional Eulerian numbers and $q-$Eulerian numbers combinatorially. In this paper, the authors give a combinatorial interpretation to the general Eulerian numbers defined on general arithmetic progressions { a, a+d, a+2d,...}. 
Tingyao Xiong, Jonathan I. Hall, Hung-ping Tsao
math.CO