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Number of n X n arrays of squares of integers summing to 18.
1

%I #11 Dec 22 2023 10:52:42

%S 30,4656,1785640,620034300,186034854330,41535948202896,

%T 6215087324054848,583572966788128320,34534249243423434450,

%U 1358435234100803814340,37831746939409059248040,788796221709817955804040,12886433906907110589156390,171056501049470927711917200

%N Number of n X n arrays of squares of integers summing to 18.

%C All such sequences have holonomic recurrences (cf. comment in A159359). - _Georg Fischer_, Feb 17 2022

%H R. H. Hardin, <a href="/A159401/b159401.txt">Table of n, a(n) for n = 2..100</a>

%H Vaclav Kotesovec, <a href="/A159401/a159401.txt">G.f. for A159401</a>

%H <a href="/index/Rec#order_37">Index entries for linear recurrences with constant coefficients</a>, signature (37, -666, 7770, -66045, 435897, -2324784, 10295472, -38608020, 124403620, -348330136, 854992152, -1852482996, 3562467300, -6107086800, 9364199760, -12875774670, 15905368710, -17672631900, 17672631900, -15905368710, 12875774670, -9364199760, 6107086800, -3562467300, 1852482996, -854992152, 348330136, -124403620, 38608020, -10295472, 2324784, -435897, 66045, -7770, 666, -37, 1).

%F G.f.: see link above. - _Vaclav Kotesovec_, Dec 04 2012

%K nonn

%O 2,1

%A _R. H. Hardin_, Apr 11 2009