On permutation trinomials of type x2ps+r+xps+r+λxr

We determine all permutation trinomials of type x(2ps+r) + x(ps+r) + lambda x(r) over the finite field F-pt when (2p(s) + r)(4) < p(t). This partially extends a previous result by Bhattacharya and Sarkar in the case p = 2, r = 1. (C) 2017 Elsevier Inc. All rights reserved