Severus Alexander AE20 of Nicaea, Bithyna. 4.1 g.

Obv: M AVR SEV ALEXANDROC AVG, laureate, draped, cuirassed bust right.
Rev: N-IK-AI-E/WI (sic), between three standards. Engraver's
error (WI instead of WN). 
 
RecGen 617 var (bust type with this obv legend; WI in ex.)
ARC coins, item 064-2010358, Dec. 2010

Notes: 
- BMC 103 var (obv legend ending and bust type)
- BMC 104 var (obv legend ending and bust type)
- SNG Copenhagen 520 var (obv legend ending)
- RecGen 617 var (bust type with this obv legend)

Courtesy of ARC coins, Switzerland, on vcoins.com, Dec. 2010