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A292281 Number of magic labelings of the prism graph I X C_6 having magic sum n. 6
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 (list; graph; refs; listen; history; text; internal format)
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R. P. Stanley, Examples of Magic Labelings, Unpublished Notes, 1973 [Cached copy, with permission]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

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Last modified February 23 02:29 EST 2019. Contains 320411 sequences. (Running on oeis4.)