A005645 Number of sensed 3-connected planar maps with n edges.

1, 0, 1, 2, 3, 4, 15, 32, 89, 266, 797, 2496, 8012, 26028, 85888, 286608, 965216, 3278776, 11221548, 38665192, 134050521, 467382224, 1638080277, 5768886048, 20407622631, 72494277840, 258527335373, 925322077852, 3323258053528, 11973883092034, 43273374700200, 156836969693756, 569967330200576, 2076647113454878, 7584534277720818, 27764845224462192, 101862027752012402, 374484866509396780, 1379489908513460150

Offset: 6

Author

N. J. A. Sloane

Keywords

• nonn

References

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

Links

• N. J. A. Sloane, Table of n, a(n) for n = 6..50
• T. R. S. Walsh, Number of sensed planar maps with n edges and m vertices
• T. R. S. Walsh, Counting nonisomorphic three-connected planar maps, J. Combin. Theory Ser. B 32 (1982), no. 1, 33-44.

Crossrefs

Cf. A002840 (unsensed), A239893.

Formula

a(n) = Sum_{k=4..n-2} A239893(k, n+2-k). - Andrew Howroyd, Mar 27 2021

Extensions

More terms and b-file added by N. J. A. Sloane, May 08 2012