Clawfree graphs erratum... A022562

Gordon Royle gordon at
Fri May 16 10:16:59 CEST 2003

A022562 gives the numbers of clawfree graphs, but I disagree with the
last entry...

I think it should be 1728404 rather than 1728403...

Brendan McKay has independently confirmed this observation; if anyone
else is willing and able to check this, then please confirm that

contains 1728404 distinct 12-vertex connected clawfree graphs. They are
stored in g6 format, which is described

and a reading program given.

The next number in the sequence (13-vertex connected clawfree graphs)
is  23805256.

NB Is the online form the appropriate mechanism for *extending*
sequences? Is the original author of a sequence permitted to check an
extension to their sequence before it is accepted?

Dr. Gordon F Royle,,
gordon at

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