OFFSET
1,23
LINKS
EXAMPLE
01: 1;
02: 0,1;
03: 0,0;
04: 0,0,1;
05: 0,0,1;
06: 0,0,1,1;
07: 0,0,1,0;
08: 0,0,1,2,1;
09: 0,0,1,0,0;
10: 0,0,1,6,2,1;
11: 0,0,1,0,2,0;
12: 0,0,1,22,12,1,1;
13: 0,0,1,0,31,0,0;
14: 0,0,1,110,220,7,1,1;
15: 0,0,1,0,1606,0,1,0;
16: 0,0,1,792,16828,388,9,1,1;
17: 0,0,1,0,193900,0,6,0,0;
18: 0,0,1,7805,2452818,406824,267,8,1,1;
19: 0,0,1,0,32670330,0,3727,0,0,0;
20: 0,0,1,97546,456028474,1125022325,483012,741,13,1,1;
21: 0,0,1,0,6636066099,0,69823723,0,1,0,0;
22: 0,0,1,1435720,100135577747,3813549359274,14836130862,2887493,?,14,1,1;
23: 0,0,1,0,1582718912968,0,?,0,?,0,0;
CROSSREFS
The sum of the n-th row is A186724(n).
Connected k-regular simple graphs with girth at least 4: A186724 (any k), this sequence (triangle); specified degree k: A185114 (k=2), A014371 (k=3), A033886 (k=4), A058275 (k=5), A058276 (k=6), A181153 (k=7), A181154 (k=8), A181170 (k=9).
Triangular arrays C(n,k) counting connected simple k-regular graphs on n vertices with girth *at least* g: A068934 (g=3), this sequence (g=4), A186715 (g=5), A186716 (g=6), A186717 (g=7), A186718 (g=8), A186719 (g=9).
KEYWORD
nonn,tabf,hard
AUTHOR
Jason Kimberley, Sep to Dec 2011.
STATUS
approved