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

2,1

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

Crossrefs

Sequence in context: A050648 A292695 A070903 * A160302 A002672 A027515

Adjacent sequences: A159383 A159384 A159385 * A159387 A159388 A159389

Keyword

nonn

Author

R. H. Hardin, Apr 11 2009

Status

approved