Q: what is error 4mem/62/40000000: x7f22e190 on macbook pro

That is indeed a memory error. But exactly what the rest of the codes mean is unpublished.

In current Macs, those errors do not typically come clean by simple steps such as re-seating, swapping positions, or contact-cleaning. You almost always will be forced to replace the modules. so if you were ever contemplating a RAM upgrade, this is your excuse.

Hardware problem, memory related. RAM or bad bank.

Is this OEM RAM or you have you upgraded?  Is this a rMBP?

Most RAM from reputable dealer is a life time warranty.  Apple is 1-yr warranty or extended.

See https://eshop.macsales.com/shop/apple/memory

or http://www.crucial.com/usa/en/systemscanner?gclid=CITShJerq80CFUiPfgodfe0Jfw&ef_ id=V0oJkgAAAAfFFtNx:20160616005548:s

In or out of warranty you can get a free over the counter 'Apple Service Diagnostics' test

Genius reservation http://www.apple.com/retail/geniusbar/

on-line https://getsupport.apple.com/GetproductgroupList.action

check warranty https://selfsolve.apple.com/agreementWarrantyDynamic.do