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A185214
Number of disconnected regular simple graphs on n vertices with girth at least 4.
17
0, 0, 1, 1, 2, 1, 2, 1, 3, 2, 4, 3, 7, 5, 10, 8, 22, 12, 54, 20, 218, 62, 1436, 1731, 27810, 197981, 2613814, 33117962, 463707741, 6709514340, 102306352539, 1597440872801
OFFSET
0,5
CROSSREFS
This sequence is the row sum sequence of A185204.
Regular graphs, of any degree, with girth at least 4: A186724 (connected), this sequence (disconnected), A185314 (not necessarily connected).
Disconnected k-regular simple graphs with girth at least 4: this sequence (any k), A185204 (triangle); specified degree k: A185224 (k=2), A185234 (k=3), A185244 (k=4), A185254 (k=5), A185264 (k=6), A185274 (k=7), A185284 (k=8), A185294 (k=9).
Sequence in context: A161257 A161282 A226517 * A241719 A269572 A029198
KEYWORD
nonn,more,hard
AUTHOR
Jason Kimberley, Mar 26 2012
EXTENSIONS
a(31) corrected by the author, propagated from A185244, Jan 05 2013
STATUS
approved