The McKay-Thompson series of Mathieu Moonshine modulo two
  In this note, we describe the parity of the coefficients of the McKay-Thompson series of Mathieu moonshine. As an application, we prove a conjecture of Cheng, Duncan and Harvey stated in connection with Umbral moonshine for the case of Mathieu moonshine. 
Thomas Creutzig, Gerald Hoehn, Tsuyoshi Miezaki
math.NT