The Brainwave Sofa goes on display Wednesday at the Bits ‘n Pieces Exhibition in New York. If you happen to stop by the show, please have a seat on the brain couch — and let us know if it’s comfy.

We first introduce three methods of finding the sum of the first n terms for an arithmetic sequence of higher order, and then display another method by some formal derivatives of which are defined.

VMS is the standard naval electronic chart display and information system (ECDIS-N), which is being deployed across the Navy's fleet of surface ships and submarines.