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 A112619 Number of connected simple graphs with n vertices, n+2 edges, and vertex degrees no more than 4. 7
 0, 0, 0, 1, 4, 18, 79, 326, 1278, 4875, 17978, 64720, 227842, 787546, 2678207, 8982754, 29761361, 97558039, 316778169, 1019996738, 3259673935, 10347077497, 32644696187, 102425388286, 319754805262 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,5 LINKS Table of n, a(n) for n=1..25. J. B. Hendrickson and C. A. Parks, Generation and Enumeration of Carbon skeletons, J. Chem. Inf. Comput. Sci., 31 (1991), 101-107. See Table 2, column 3 on page 103. Michael A. Kappler, GENSMI: Exhaustive Enumeration of Simple Graphs. [gives different a(18)] PROG (nauty/bash) for n in {4..15}; do geng -c -D4 \${n} \$((n+2)):\$((n+2)) -u; done # Andrey Zabolotskiy, Nov 24 2017 CROSSREFS The analogs for n+k edges with k = -1, 0, ..., 7 are: A000602, A036671, A112410, this sequence, A112408, A112424, A112425, A112426, A112442. Cf. A121941. Sequence in context: A219137 A240342 A208309 * A196810 A177755 A037965 Adjacent sequences: A112616 A112617 A112618 * A112620 A112621 A112622 KEYWORD nonn AUTHOR Jonathan Vos Post, Dec 21 2005 EXTENSIONS Corrected offset and new name from Andrey Zabolotskiy, Nov 24 2017 a(18) corrected and a(19)-a(25) added by Georg Grasegger, Jun 05 2023 STATUS approved

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Last modified April 16 22:47 EDT 2024. Contains 371755 sequences. (Running on oeis4.)