A159397 Number of n X n arrays of squares of integers summing to 16.
5, 3987, 960197, 243293450, 49328395731, 7138321890616, 666179701320556, 38558976229027926, 1439078695947198175, 37055970405356439240, 701629710103618241661, 10289171538319337074541, 121736692023067368010505
Offset: 2
Keywords
Links
- R. H. Hardin, Table of n, a(n) for n=2..100
- Index entries for linear recurrences with constant coefficients, signature (33, -528, 5456, -40920, 237336, -1107568, 4272048, -13884156, 38567100, -92561040, 193536720, -354817320, 573166440, -818809200, 1037158320, -1166803110, 1166803110, -1037158320, 818809200, -573166440, 354817320, -193536720, 92561040, -38567100, 13884156, -4272048, 1107568, -237336, 40920, -5456, 528, -33, 1).
Formula
Empirical G.f.: -x - x*(1+x)*(1 -29*x + 4379*x^2 + 821431*x^3 + 212904294*x^4 + 41572005795*x^5 + 5592296001394*x^6 + 449779113080002*x^7 + 19634897290562828*x^8 + 461755603301498981*x^9 + 6109738979241997636*x^10 + 47748225885297619913*x^11 + 229005554540179223339*x^12 + 691824816742731558421*x^13 + 1336833271423720702097*x^14 + 1664132445913632199036*x^15 + 1336833271423720702097*x^16 + 691824816742731558421*x^17 + 229005554540179223339*x^18 + 47748225885297619913*x^19 + 6109738979241997636*x^20 + 461755603301498981*x^21 + 19634897290562828*x^22 + 449779113080002*x^23 + 5592296001394*x^24 + 41572005795*x^25 + 212904294*x^26 + 821431*x^27 + 4379*x^28 - 29*x^29 + x^30)/(-1+x)^33. - Vaclav Kotesovec, Nov 30 2012
Comments