A027484 a(n) = n*(n^4-1)/2.
15, 120, 510, 1560, 3885, 8400, 16380, 29520, 49995, 80520, 124410, 185640, 268905, 379680, 524280, 709920, 944775, 1238040, 1599990, 2042040, 2576805, 3218160, 3981300, 4882800, 5940675, 7174440, 8605170, 10255560, 12149985
Offset: 2
Links
- Vincenzo Librandi, Table of n, a(n) for n = 2..1000
- S. Gartenhaus, Odd Order Pandiagonal Latin and Magic Cubes in Three and Four Dimensions, arXiv:math/0210275 [math.CO], 2002.
- Index entries for linear recurrences with constant coefficients, signature (6,-15,20,-15,6,-1).
Crossrefs
First subdiagonal of A027479.
Programs
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Magma
[n*(n^4 - 1)/2: n in [2..50]];// Vincenzo Librandi, Dec 29 2012
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Mathematica
Table[(m^5 - m)/2, {m, 34}] (* Zerinvary Lajos, Mar 21 2007 *) LinearRecurrence[{6,-15,20,-15,6,-1},{15,120,510,1560,3885,8400},30] (* Harvey P. Dale, Aug 02 2024 *) -
PARI
a(n)=n*(n^4-1)/2 \\ Charles R Greathouse IV, Oct 21 2022
Formula
From Chai Wah Wu, Apr 08 2021: (Start)
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n > 7.
G.f.: 15*x^2*(x + 1)^2/(x - 1)^6. (End)
Comments