− | * [http://www.research.att.com/~njas/sequences/Seis.html Sloane's Online Encyclopedia of Integer Sequences] | + | * [[Outbound Link:=http://www.research.att.com/~njas/sequences/Seis.html|[http://www.research.att.com/~njas/sequences/Seis.html Sloane's On-Line Encyclopedia of Integer Sequences]]] |