Small values of coefficients of a half Lerch sum

Abstract

Andrews, Dyson and Hickerson proved many interesting properties of coefficients for a Ramanujan’s [Formula: see text]-hypergeometric series by relating it to real quadratic field [Formula: see text] and using the arithmetic of [Formula: see text] to solve a conjecture of Andrews on the distributions of its Fourier coefficients. Motivated by Andrews’s conjecture, we discuss an interesting [Formula: see text]-hypergeometric series which comes from a Lerch sum and rank and crank moments for partitions and overpartitions. We give Andrews-like conjectures for its coefficients. We obtain partial results on the distributions of small values of its coefficients toward these conjectures.