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Number of sensed 3-connected planar maps with n edges.
(Formerly M0599)
3

%I M0599 #33 Mar 31 2021 04:55:47

%S 1,0,1,2,3,4,15,32,89,266,797,2496,8012,26028,85888,286608,965216,

%T 3278776,11221548,38665192,134050521,467382224,1638080277,5768886048,

%U 20407622631,72494277840,258527335373,925322077852,3323258053528,11973883092034,43273374700200,156836969693756,569967330200576,2076647113454878,7584534277720818,27764845224462192,101862027752012402,374484866509396780,1379489908513460150

%N Number of sensed 3-connected planar maps with n edges.

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%H N. J. A. Sloane, <a href="/A005645/b005645.txt">Table of n, a(n) for n = 6..50</a>

%H T. R. S. Walsh, <a href="/A007401/a007401.pdf">Number of sensed planar maps with n edges and m vertices</a>

%H T. R. S. Walsh, <a href="https://doi.org/10.1016/0095-8956(82)90074-0">Counting nonisomorphic three-connected planar maps</a>, J. Combin. Theory Ser. B 32 (1982), no. 1, 33-44.

%F a(n) = Sum_{k=4..n-2} A239893(k, n+2-k). - _Andrew Howroyd_, Mar 27 2021

%Y Cf. A002840 (unsensed), A239893.

%K nonn

%O 6,4

%A _N. J. A. Sloane_

%E More terms and b-file added by _N. J. A. Sloane_, May 08 2012