A292281 Number of magic labelings of the prism graph I X C_6 having magic sum n.

1, 20, 167, 867, 3322, 10309, 27410, 64770, 139479, 278674, 523457, 933725, 1594008, 2620411, 4168756, 6444020, 9711165, 14307456, 20656363, 29283143, 40832198, 56086305, 75987814, 101661910, 134442035, 175897566, 227863845, 292474657, 372197252, 469870007, 588742824

Offset

0,2

Links

Table of n, a(n) for n=0..30.

R. P. Stanley, Examples of Magic Labelings, Unpublished Notes, 1973 [Cached copy, with permission]

Formula

a(n) = A244879(n) + 2*Sum_{i=0..n-1} A244879(i).

Conjectures from Colin Barker, Sep 13 2017: (Start)

G.f.: (1 + x)*(1 + 11*x + 24*x^2 + 11*x^3 + x^4) / (1 - x)^8.

a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8) for n>7.

(End)

Mathematica

f[n_] := SeriesCoefficient[(1 + 11 x + 24 x^2 + 11 x^3 + x^4)/(1 - x)^7, {x, 0, n}]; Table[f[n] + 2 Sum[f[i], {i, 0, n - 1}], {n, 0, 24}] (* Michael De Vlieger, Sep 15 2017 *)

Crossrefs

Cf. A019298, A061927, A244497, A244879, A244873, A289992.

Sequence in context: A056114 A281204 A186259 * A056932 A304508 A010826

Adjacent sequences: A292278 A292279 A292280 * A292282 A292283 A292284

Keyword

nonn

Author

David J. Seal, Sep 13 2017

Status

approved