“…The Fourier coefficients are of interest, [Bm,BDHI,HA,Iw1,Iw2,Ms,Pt1,Pt2,Tr,Sr1,Sb1,Vk] The order of magnitude of the Fourier coefficients and their sums are basic issues, even for nonarithmetic groups [DI,Iw2,Pt1,Pt2,Sr1,Sb2]. Hecke gave the argument for the elementary bound valid for Γ cofinite with a cusp at infinity |a(n)|e…”