Linksys 1900AC V1 sha256sum not matching

I am not getting a match for the checksum strings when verifying downloads.
I am getting the download file for the install at this URL:[Model*~]=1900AC+ under column label: Firmware OpenWrt Install. The link I am using is: (i'm limited to two links) The byte count on this file is 6.4 meg.
My 1900AC has been reset to factory settings.

The checksum reference I am using is from URL:
using this download link: linksys-wrt1900ac-initramfs-kernel.bin File size is 3.9 meg.

I know very little about this, but I think I have followed directions although they are a bit complex. Please resolve this issue either from my side or yours? thanks chop

A quick check of both the factory and sysupgrade images for the mamba device are in agreement with the checksums at the download page. Are you confusing the two images, which are different in size and function; if going from OEM to OpenWrt use the factory image.