Does
First Base qualify ? Babe Ruth
One Way Street - Harvey Mandel (Baby Batter)
Uno Ino - " (The Snake)
Hit Single #1 - Hot Tuna (America's Choice)
One Step Ahead - Long John Baldry (It Still Ain't Easy)
One Life to Live - John Mayall's Blues Breakers (Chicago Line)
How about this: Mark-Almond/ 1.
They were Jon Mark & Mark Almond. They had 2 albums, both from Blue Thumb Records in 1982. They were titled simply "1", and "2".
Anybody ever hear of these guys? The music was good. Very different, and hypnotic. 
Re Jon Mark-Johnny Almond, they along with Steve Thompson on bass were the band on
Turning Point as noted by konut. One of Mayall's many ground breaking offerings. Can you think of another blues or rock album that doesn't have any drums ?
Their inital release was simply
Mark-Almond, then
Mark-Almond II, those around '71-'72. In '76 they released
To the Heart, and their final offering I'm aware of was
Other Peoples Rooms in '78. Their 1st release was a gray sleeve with a flip top, II was the purple picture frames. They both had at least one individual release, possibly more. Like putz I saw them circa '72, only by themselves. A class act, outstanding musicianship.
Apologies for the sidetrack Wayne.
