This is an announcement for the paper "Sequence-singular operators" by Gleb Sirotkin and Ben Wallis. Abstract: In this paper we study two types of collections of operators on a Banach space on the subject of forming operator ideals. One of the types allows us to construct an uncountable chain of closed ideals in each of the operator algebras $\mathcal{L}(\ell_1\oplus\ell_q)$, $1<q<\infty$, and $\mathcal{L}(\ell_1\oplus c_0)$. This finishes answering a longstanding question of Pietsch. Archive classification: math.FA Mathematics Subject Classification: 46B06, 46B25, 46B45, 47L10, 47L20 Remarks: 13 pages Submitted from: z1019463@students.niu.edu The paper may be downloaded from the archive by web browser from URL http://front.math.ucdavis.edu/1509.01485 or http://arXiv.org/abs/1509.01485