A006825 Number of connected regular bipartite graphs of degree 5 with 2n nodes.

1, 1, 4, 41, 1981, 304495, 78322915, 27033154060, 11934777413004, 6593485023087880, 4485517185017428244, 3707462300996566329965, 3680029088808677189795063, 4341813441626419937873317841, 6033239205199247162872884404386, 9792722283774374706204648839780148

Offset: 5

Author

N. J. A. Sloane

Keywords

• nonn
• hard

References

• CRC Handbook of Combinatorial Designs, 1996, p. 648.
• I. A. Faradzev, Constructive enumeration of combinatorial objects, pp. 131-135 of Problèmes combinatoires et théorie des graphes (Orsay, 9-13 Juillet 1976). Colloq. Internat. du C.N.R.S., No. 260, Centre Nat. Recherche Scient., Paris, 1978.
• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

• M. Meringer, Tables of Regular Graphs
• B. D. McKay and E. Rogoyski, Latin squares of order ten, Electron. J. Combinatorics, 2 (1995) #N3.

Crossrefs

Column 5 of A008326.

Cf. A006823, A006824, A333731.

Formula

Inverse Euler transform of A333731. - Andrew Howroyd, Apr 03 2020

Extensions

More terms from Eric Rogoyski, May 15 1997

Terms a(12) and beyond from Andrew Howroyd, Apr 03 2020