Looks like they play five games against the Flyers, and one of NYR/NYI; only see the Penguins 4x in the regular season.
Rob Rossi @RobRossi_Trib
.@penguins play 5 apiece against @NYRangers @NYIslanders and 4 each against @NHLFlyers @NHLDevils #pens
Frank Seravalli @DNFlyers
Flyers per league source: 5 v. NYR, NJ; 4 v. PIT, NYI; 5 East on road: WPG,MTL,TOR,BUF,TB; 5 East at home: BOS,OTT,FLA,CAR,WSH. H/H w/ othrs