A001437 Number of connected graphs with n nodes and ceiling(n(n-1)/4) edges. (Formerly M1538 N0601)

1, 1, 2, 5, 22, 138, 1579, 33366, 1348674, 105925685, 15968704512, 4520384306832, 2402814904220039, 2425664021535713098, 4647586298937784001491, 16787189663016572148130262, 114716901953374968257425111039

Offset

2,3

References

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Sean A. Irvine, Table of n, a(n) for n = 2..40

M. L. Stein and P. R. Stein, Enumeration of Linear Graphs and Connected Linear Graphs up to p = 18 Points. Report LA-3775, Los Alamos Scientific Laboratory of the University of California, Los Alamos, NM, Oct 1967.

Crossrefs

Largest entries in the rows of the table in A054924.

Sequence in context: A111542 A342432 A246542 * A067549 A262842 A361331

Adjacent sequences: A001434 A001435 A001436 * A001438 A001439 A001440

Keyword

nonn,nice

Author

N. J. A. Sloane.

Extensions

More terms from Sean A. Irvine, Jul 24 2012

Status

approved