A173758 Partial sums of A006820.

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.

Links

Table of n, a(n) for n=0..27.

Formula

a(n) = Sum_{k=0..n} A006820(k). [corrected by Georg Fischer, Sep 28 2021]

Crossrefs

Cf. A006820, A033301, A033483.

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

Adjacent sequences: A173755 A173756 A173757 * A173759 A173760 A173761

Keyword

nonn

Author

Jonathan Vos Post, Feb 23 2010

Extensions

Corrected by Jason Kimberley, Mar 29 2010

Status

approved