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 A185131 Irregular triangle C(n,g) counting connected trivalent simple graphs on 2n vertices with girth  at least g. 18
 1, 2, 1, 5, 2, 19, 6, 1, 85, 22, 2, 509, 110, 9, 1, 4060, 792, 49, 1, 41301, 7805, 455, 5, 510489, 97546, 5783, 32, 7319447, 1435720, 90938, 385, 117940535, 23780814, 1620479, 7574, 1, 2094480864, 432757568, 31478584, 181227, 3, 40497138011, 8542471494 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,2 COMMENTS The first column is for girth at least 3. The row length is incremented to g-2 when 2n reaches A000066(g). LINKS Jason Kimberley, Table of i, a(i) for i = 2..59 (n = 2..16) B. Brinkmann, J. Goedgebeur, B. D. McKay, Generation of cubic graphs, Discr. Math. Theor. Comp. Sci. 13 (2) (2011) 69-80 House of Graphs, Cubic graphs M. Meringer, Tables of Regular Graphs EXAMPLE 1; 2, 1; 5, 2; 19, 6, 1; 85, 22, 2; 509, 110, 9, 1; 4060, 792, 49, 1; 41301, 7805, 455, 5; 510489, 97546, 5783, 32; 7319447, 1435720, 90938, 385; 117940535, 23780814, 1620479, 7574, 1; 2094480864, 432757568, 31478584, 181227, 3; 40497138011, 8542471494, 656783890, 4624501, 21; 845480228069, 181492137812, 14621871204, 122090544, 546, 1; 18941522184590, 4127077143862, 345975648562, 3328929954, 30368, 0; 453090162062723, ?, ?, 93990692595, 1782840, 1; 11523392072541432, ?, ?, 2754222605376, 95079083, 3; 310467244165539782, ?, ?, ?, 4686063120, 13; 8832736318937756165, ?, ?, ?, 220323447962, 155; ?, ?, ?, 10090653722861, 4337; CROSSREFS Connected 3-regular simple graphs with girth at least g: this sequence (triangle); chosen g: A002851 (g=3), A014371 (g=4), A014372 (g=5), A014374 (g=6), A014375 (g=7), A014376 (g=8). Connected 3-regular simple graphs with girth exactly g: A198303 (triangle); chosen g: A006923 (g=3), A006924 (g=4), A006925 (g=5), A006926 (g=6), A006927 (g=7). Triangular arrays C(n,g) counting connected simple k-regular graphs on n vertices with girth at least g: this sequence (k=3), A184941 (k=4), A184951 (k=5), A184961 (k=6), A184971 (k=7), A184981 (k=8). Sequence in context: A115345 A194092 A140165 * A199660 A141483 A230038 Adjacent sequences:  A185128 A185129 A185130 * A185132 A185133 A185134 KEYWORD nonn,hard,tabf AUTHOR Jason Kimberley, Jan 09 2012 EXTENSIONS Terms C(18,6), C(20,7) and C(21,7) from House of Graphs via Jason Kimberley, May 21 2017 STATUS approved

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Last modified April 16 05:26 EDT 2021. Contains 343030 sequences. (Running on oeis4.)