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A173758
Partial sums of A006820.
0
1, 1, 1, 1, 1, 2, 3, 5, 11, 27, 86, 351, 1895, 12673, 100841, 906332, 8943750, 95165384, 1081035906, 13027523553, 165835586734, 2222527601208, 31273800434817, 460941981112256, 7101107185967292, 114127691657536897, 1910229280483131905, 33244227211086415436
OFFSET
0,6
COMMENTS
Number of connected quartic graphs with at most n nodes.
FORMULA
a(n) = Sum_{k=0..n} A006820(k). [corrected by Georg Fischer, Sep 28 2021]
CROSSREFS
Connected regular graphs of degree k: A002851 (k=3), A006820 (k=4), A006821 (k=5), A006822 (k=6), A014377 (k=7), A014378 (k=8), A014381 (k=9), A014382 (k=10), A014384 (k=11).
Sequence in context: A009589 A098179 A055228 * A098642 A079447 A171832
KEYWORD
nonn
AUTHOR
Jonathan Vos Post, Feb 23 2010
EXTENSIONS
Corrected by Jason Kimberley, Mar 29 2010
STATUS
approved