I found something weird. In some cells, the triangle base is equal to t+1. In others, it isn't.

{6:5:135:32:103:177} (6,5,17)

(x+n)=37, (x+n)(x+n)=1369

(1369-1)/8=171, which is the 18th triangle number

t=base-1

{6:5:183:38:145:231} (6,5,20)

(x+n)=43, (x+n)(x+n)=1849

(1849-1)/8=231, which is the 21st triangle number

t=base-1

{6:5:219:42:177:271} (6,5,22)

(x+n)=47, (x+n)(x+n)=2209

(2209-1)/8=276, which is the 23rd triangle number

t=base-1

{98:59:791:252:539:1161} (98,59,127)

(x+n)=311, (x+n)(x+n)=96721

(96721-1)/8=12090, which is the 155th triangle number, but the 128th triangle number (t+1) is 8256

I'm thinking maybe there's a slightly more complex formula involving t to find the base. This is a strange coincidence if not, and you know what they say about coincidences. If it is true and there's a slightly more complicated formula for it (like maybe t+(e-n) (that's not it though)), all we'd need to do is find maybe some kind of cell transform that gives us the same t as our (e,n) in every case.