This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A159389 #12 Jun 02 2025 01:34:08 %S A159389 16,1962,350240,48299450,5030081280,346589305664,14664677168512, %T A159389 394240010602320,7283982145272800,99396267512446410, %U A159389 1059813625787601696,9216296747192215226,67545604711093622960,427985285624487838800 %N A159389 Number of n X n arrays of squares of integers summing to 13. %C A159389 All such sequences have holonomic recurrences (cf. comment in A159359). - _Georg Fischer_, Feb 17 2022 %H A159389 R. H. Hardin, <a href="/A159389/b159389.txt">Table of n, a(n) for n=2..100</a> %H A159389 <a href="/index/Rec#order_27">Index entries for linear recurrences with constant coefficients</a>, signature (27, -351, 2925, -17550, 80730, -296010, 888030, -2220075, 4686825, -8436285, 13037895, -17383860, 20058300, -20058300, 17383860, -13037895, 8436285, -4686825, 2220075, -888030, 296010, -80730, 17550, -2925, 351, -27, 1). %F A159389 Empirical G.f.: -2*x^2*(1+x)*(8 + 757*x + 150684*x^2 + 19591732*x^3 + 1902144428*x^4 + 111467309309*x^5 + 3357053495448*x^6 + 49669712820552*x^7 + 379085540031904*x^8 + 1572597871783886*x^9 + 3663335172842872*x^10 + 4854870652776840*x^11 + 3663335172842872*x^12 + 1572597871783886*x^13 + 379085540031904*x^14 + 49669712820552*x^15 + 3357053495448*x^16 + 111467309309*x^17 + 1902144428*x^18 + 19591732*x^19 + 150684*x^20 + 757*x^21 + 8*x^22)/(-1+x)^27. - _Vaclav Kotesovec_, Nov 30 2012 %K A159389 nonn %O A159389 2,1 %A A159389 _R. H. Hardin_ Apr 11 2009