A174020 Number of reduced 3 X 3 magilatin squares with magic sum n.

12, 12, 24, 60, 144, 216, 480, 444, 780, 996, 1404, 1548, 2460, 2640, 3696, 4128, 5508, 5904, 8148, 8220, 10824, 11688, 14364, 14904, 19380, 19596, 24108, 24936, 30240, 31104, 37992, 37920, 45312, 47148, 54756, 55404, 66000, 66252, 76920, 78288

Offset: 3

Author

Thomas Zaslavsky, Mar 05 2010

Keywords

• nonn

Comments

A magilatin square has equal row and column sums and no number repeated in any row or column. It is reduced if the least value in it is 0.

a(n) is given by a quasipolynomial of degree 4 and period 840.

References

• Matthias Beck and Thomas Zaslavsky, An enumerative geometry for magic and magilatin labellings, Annals of Combinatorics, 10 (2006), no. 4, pages 395-413. MR 2007m:05010. Zbl 1116.05071.

Links

• Thomas Zaslavsky, Table of n, a(n) for n = 3..10000.
• Matthias Beck and Thomas Zaslavsky, Six Little Squares and How Their Numbers Grow , J. Int. Seq. 13 (2010), 10.6.2.
• Matthias Beck and Thomas Zaslavsky, "Six Little Squares and How their Numbers Grow" Web Site: Maple worksheets and supporting documentation.
• Index entries for linear recurrences with constant coefficients, signature (-2, -3, -3, -2, 0, 3, 6, 9, 10, 9, 5, 0, -6, -11, -14, -14, -11, -6, 0, 5, 9, 10, 9, 6, 3, 0, -2, -3, -3, -2, -1).

Crossrefs

Cf. A173549 (all magilatin squares), A173730 (symmetry types), A174021 (reduced symmetry types), A174018 (reduced squares by largest value).

Formula

G.f.: 12*x^3/[(x-1)*(x^2-1)] - 108*x^5/[(x-1)*(x^2-1)^2] - 72*x^5/[(x-1)*(x^4-1)] - 72*x^5/[(x^3-1)*(x^2-1)] - 36*x^5/(x^5-1) + 72*x^7/[(x-1)*(x^2-1)^3] + 144*x^7/[(x-1)*(x^2-1)*(x^4-1)] + 72*x^7/[(x-1)*(x^6-1)] + 72*x^7/[(x^2-1)^2*(x^3-1)] + 72*x^7/[(x^2-1)*(x^5-1)] + 72*x^7/(x^7-1) + 72*x^9/[(x-1)*(x^4-1)^2] + 144*x^9/[(x^2-1)*(x^3-1)*(x^4-1)] + 144*x^9/[(x^3-1)*(x^6-1)] + 72*x^9/[(x^4-1)*(x^5-1)] + 72*x^11/[(x^3-1)*(x^4-1)^2] + 72*x^11/[(x^3-1)*(x^8-1)] + 72*x^11/[(x^5-1)*(x^6-1)] + 72*x^13/[(x^5-1)*(x^8-1)].

Extensions

"Distinct" values (incorrect) deleted by Thomas Zaslavsky, Apr 24 2010