A159405 Number of n X n arrays of squares of integers summing to 20.

18, 7326, 2995908, 1455763635, 622097389872, 206307703531587, 47588288640846912, 7046841590377578801, 653092799056599247740, 39121901776525814650965, 1603648230996545513760708, 47634024309523287458232228, 1076943060410127149424142230

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

Vaclav Kotesovec, G.f. for A159405

Index entries for linear recurrences with constant coefficients, signature (41, -820, 10660, -101270, 749398, -4496388, 22481940, -95548245, 350343565, -1121099408, 3159461968, -7898654920, 17620076360, -35240152720, 63432274896, -103077446706, 151584480450, -202112640600, 244662670200, -269128937220, 269128937220, -244662670200, 202112640600, -151584480450, 103077446706, -63432274896, 35240152720, -17620076360, 7898654920, -3159461968, 1121099408, -350343565, 95548245, -22481940, 4496388, -749398, 101270, -10660, 820, -41, 1).

Formula

G.f.: see link above. - Vaclav Kotesovec, Dec 04 2012

Crossrefs

Sequence in context: A366518 A232595 A335685 * A265450 A213402 A248804

Adjacent sequences: A159402 A159403 A159404 * A159406 A159407 A159408

Keyword

nonn

Author

R. H. Hardin, Apr 11 2009

Status

approved