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 A046742 Triangle of number of connected graphs with k >= 1 edges and n nodes (2 <= n <= k+1). 4
 1, 0, 1, 0, 1, 2, 0, 0, 2, 3, 0, 0, 1, 5, 6, 0, 0, 1, 5, 13, 11, 0, 0, 0, 4, 19, 33, 23, 0, 0, 0, 2, 22, 67, 89, 47, 0, 0, 0, 1, 20, 107, 236, 240, 106, 0, 0, 0, 1, 14, 132, 486, 797, 657, 235, 0, 0, 0, 0, 9, 138, 814, 2075, 2678, 1806, 551, 0, 0, 0, 0, 2, 95, 1454, 8404, 22950, 33851, 28908 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,6 REFERENCES G. A. Baker et al., High-temperature expansions for the spin-1/2 Heisenberg model, Phys. Rev., 164 (1967), 800-817. LINKS Gordon Royle, Small graphs 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. doi: 10.2172/4180737. Table 1 (complete up to 18 nodes) EXAMPLE 1; 0 1; 0 1 2; 0 0 2 3; 0 0 1 5 6; 0 0 1 5 13 11; 0 0 0 4 19 33 23; 0 0 0 2 22 67 89 47; 0 0 0 1 20 107 236 240 106; 0 0 0 1 14 132 486 797 657 235; 0 0 0 0 9 138 814 2075 2678 1806 551; 0 0 0 0 5 126 1169 4495 8548 8833 5026 1301; 0 0 0 0 2 95 1454 8404 22950 33851 28908 13999 3159; 0 0 0 0 1 64 1579 13855 53863 109844 130365 93569 39260 7741; 0 0 0 0 1 40 1515 20303 112618 313670 499888 489387 300748 110381 19320; 0 0 0 0 0 21 1290 26631 211866 803905 1694642 2179949 1799700 959374 311465 ... ... (so with 5 edges there's 1 graph with 4 nodes, 5 with 5 nodes and 1 with 6 nodes). CROSSREFS Cf. A002905 (row sums), A008406, A046751, A054923, A054924 (transpose), A001349 (column sums). Sequence in context: A296441 A091008 A111006 * A263138 A274637 A178516 Adjacent sequences:  A046739 A046740 A046741 * A046743 A046744 A046745 KEYWORD nonn,easy,nice,tabl AUTHOR STATUS approved

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Last modified December 12 23:01 EST 2018. Contains 318081 sequences. (Running on oeis4.)