A159386 Number of n X n arrays of squares of integers summing to 12.

8, 1857, 232740, 26296475, 2128426860, 110964458710, 3533207162352, 73077185537370, 1067559034014900, 11805270721428855, 104131103837358468, 762072014041423813, 4768129728862470880, 26106675760931007900, 127411116947126838720, 562536757736562399012

Offset: 2

Author

R. H. Hardin, Apr 11 2009

Keywords

• nonn

Comments

All such sequences have holonomic recurrences (cf. comment in A159359). - Georg Fischer, Feb 17 2022

Links

• R. H. Hardin, Table of n, a(n) for n=2..100
• Index entries for linear recurrences with constant coefficients, signature (25, -300, 2300, -12650, 53130, -177100, 480700, -1081575, 2042975, -3268760, 4457400, -5200300, 5200300, -4457400, 3268760, -2042975, 1081575, -480700, 177100, -53130, 12650, -2300, 300, -25, 1).

Formula

Empirical G.f.: -x^2*(1+x)*(8 + 1649*x + 187066*x^2 + 20829609*x^3 + 1515837476*x^4 + 63614656244*x^5 + 1276374119248*x^6 + 12185198155972*x^7 + 58755893406228*x^8 + 149482468806702*x^9 + 204117353324396*x^10 + 149482468806702*x^11 + 58755893406228*x^12 + 12185198155972*x^13 + 1276374119248*x^14 + 63614656244*x^15 + 1515837476*x^16 + 20829609*x^17 + 187066*x^18 + 1649*x^19 + 8*x^20)/(-1+x)^25. - Vaclav Kotesovec, Nov 30 2012