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A244871 Number of magic labelings with magic sum n of 3rd graph shown in link. 2
1, 10, 55, 217, 672, 1755, 4030, 8386, 16135, 29140, 49941, 81915, 129430, 198037, 294652, 427780, 607725, 846846, 1159795, 1563805, 2078956, 2728495, 3539130, 4541382, 5769907, 7263880, 9067345, 11229631, 13805730, 16856745, 20450296, 24661000, 29570905 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..32.

N. J. A. Sloane, Graphs for A244869-A244876.

R. P. Stanley, Examples of Magic Labelings, Unpublished Notes, 1973 [Cached copy, with permission]

Index entries for linear recurrences with constant coefficients, signature (5, -8, 0, 14, -14, 0, 8, -5, 1).

FORMULA

G.f.: (1+5*x+13*x^2+22*x^3+13*x^4+5*x^5+x^6)/((1-x)^7*(1+x)^2).

a(n) = n^6/48 + 3*n^5/16 + 77*n^4/96 + 2*n^3 + 37*n^2/12 - n*(-1)^n/32 + 89*n/32 - 3*(-1)^n/64 + 67/64. [Bruno Berselli, Jul 08 2014]

MATHEMATICA

Table[n^6/48 + 3 n^5/16 + 77 n^4/96 + 2 n^3 + 37 n^2/12 - n (-1)^n/32 + 89 n/32 - 3 (-1)^n/64 + 67/64, {n, 0, 40}] (* Bruno Berselli, Jul 08 2014 *)

CROSSREFS

Cf. A244869-A244876.

Sequence in context: A069155 A107352 A127761 * A162617 A070212 A289380

Adjacent sequences:  A244868 A244869 A244870 * A244872 A244873 A244874

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, Jul 08 2014

STATUS

approved

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Last modified February 23 05:58 EST 2019. Contains 320411 sequences. (Running on oeis4.)