This pattern can be adapted to circular knitting by knitting all the odd numbered rows.
Repeat rows 1 - 4.
Row #SideBegin RowRepeatRepeat From *End Row
1W*purl* 
2Rk2*k2-tog, yo, k1*k1
3W*purl* 
4Rk2*yo, k1, k2-tog*k1