Search for the production of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>W</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:msup><mml:mi>W</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:msup><mml:mi>W</mml:mi><mml:mo>∓</mml:mo></mml:msup></mml:math> events at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>13</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>TeV</mml:mi></mml:math>

A search for the production of events containing three W bosons predicted by the standard model is reported. The search is based on a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV recorded by the CMS experiment at the CERN LHC and corresponding to a total integrated luminosity of 35.9 fb -1 . The search is performed in final states with three leptons (electrons or muons), or with two same-charge leptons plus two jets. The observed (expected) significance of the signal for W AE W AE W production is 0.60 (1.78) standard deviations, and the ratio of the measured signal yield to that expected from the standard model is 0.34 0.62 -0.34 . Limits are placed on three anomalous quartic gauge couplings and on the production of massive axionlike particles.