A198016 Number of isomorphism classes of nanocones with 4 pentagons and a nearsymmetric boundary of length n

2, 9, 32, 89, 204, 420, 786, 1376, 2272, 3589, 5450, 8021, 11474, 16032, 21928, 29452, 38902, 50645, 65056, 82585, 103692, 128920, 158822, 194044, 235240, 283165, 338586, 402377, 475422, 558724, 653296, 760276, 880814, 1016193, 1167708, 1336797, 1524908

Offset

2,1

Links

Nico Van Cleemput, Table of n, a(n) for n = 2..75

Gunnar Brinkmann and Nico Van Cleemput, Classification and generation of nanocones, Discrete Applied Mathematics, 159 (2011), 1528-1539.

Formula

Conjectured g.f.: x^2*(-2*x^8 + 5*x^7 + x^6 + 13*x^5 + 8*x^4 + 13*x^3 + 9*x^2 + 3*x + 2)/(x^12 - 3*x^11 + 2*x^10 + x^9 - x^8 + 2*x^7 - 4*x^6 + 2*x^5 - x^4 + x^3 + 2*x^2 - 3*x + 1). [D. S. McNeil, Oct 20 2011]

Crossrefs

Sequence in context: A212873 A109770 A242512 * A082114 A332870 A074084

Adjacent sequences: A198013 A198014 A198015 * A198017 A198018 A198019

Keyword

nonn

Author

Nico Van Cleemput, Oct 20 2011

Status

approved