[seqfan] Cross-References to A006820

[Jason Kimberley]

G'day Seqfans,


It seems, to me, that the following two cross-references to A006820 are accidental.
Otherwise, would someone add a comment explaining the relationship?

%N A051266 Numbers n such that maximal value of prime divisors of reduced residue system for n is 2.
%Y A051266 .................. A006820, ....................

%N A051267 Numbers n such that maximal value of prime divisors of reduced residue system for n is 3.
%Y A051267 .................. A006820, ....................

%N A006820 Number of connected regular graphs of degree 4 (or quartic graphs) with n nodes.


Thanks,
Jason.