cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A288281 a(n) is the number of rooted maps with n edges and one face on an orientable surface of genus 5.

Original entry on oeis.org

59520825, 4304016990, 158959754226, 4034735959800, 79553497760100, 1302772718028600, 18475997006212200, 233454817237201560, 2682208751185413450, 28449551653853229900, 281858111998039476900, 2632472852850938916000, 23350616705746908461520, 197910970615681824664800, 1610886016462484019585600
Offset: 10

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Author

Gheorghe Coserea, Jun 09 2017

Keywords

Crossrefs

Rooted maps of genus 5 with n edges and f faces for 1<=f<=10: this sequence, A288282 f=2, A288283 f=3, A288284 f=4, A288285 f=5, A288286 f=6, A288287 f=7, A288288 f=8, A288289 f=9, A288290 f=10.
Column 1 of A269925.
Cf. A000108.

Programs

  • Mathematica
    Q[0, 1, 0] = 1; Q[n_, f_, g_] /; n < 0 || f < 0 || g < 0 = 0;
    Q[n_, f_, g_] := Q[n, f, g] = 6/(n + 1) ((2 n - 1)/3 Q[n - 1, f, g] + (2 n - 1)/3 Q[n - 1, f - 1, g] + (2 n - 3) (2 n - 2) (2 n - 1)/12 Q[n - 2, f, g - 1] + 1/2 Sum[l = n - k; Sum[v = f - u; Sum[j = g - i; Boole[l >= 1 && v >= 1 && j >= 0] (2 k - 1) (2 l - 1) Q[k - 1, u, i] Q[l - 1, v, j], {i, 0, g}], {u, 1, f}], {k, 1, n}]);
    a[n_] := Q[n, 1, 5];
    Table[a[n], {n, 10, 24}] (* Jean-François Alcover, Oct 17 2018 *)

Formula

G.f.: -88179*y*(y-1)^10*(675*y^8 + 9660*y^7 + 19104*y^6 - 38620*y^5 - 26606*y^4 + 51308*y^3 - 10784*y^2 - 5416*y + 1354)/(y-2)^29, where y=A000108(x).