A318630 Number of 9-member subsets of [9*n] whose elements sum to a multiple of n.

0, 1, 24310, 1562331, 23535820, 177232627, 886322982, 3381098545, 10639125640, 28987537806, 70625252863, 157366449604, 325949658015, 635299897870, 1176174344125, 2083664997876, 3553074951283, 5859727868575, 9383313282102, 14637413449945, 22304900540890

Offset: 0

Author

Alois P. Heinz, Aug 30 2018

Keywords

• nonn
• easy

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..10000
• Index entries for linear recurrences with constant coefficients, signature (6,-15,22,-27,36,-42,36,-27,23,-21,21,-23,27,-36,42,-36,27,-22,15,-6,1).

Crossrefs

Row n=9 of A318557.

Formula

G.f.: -x*(9*x^20 +24256*x^19 +1416550*x^18 [phone]*x^17 [phone]*x^16 [phone]*x^15 [phone]*x^14 [phone]*x^13 [phone]*x^12 [phone]*x^11 [phone]*x^10 [phone]*x^9 [phone]*x^8 [phone]*x^7 [phone]*x^6 [phone]*x^5 [phone]*x^4 [phone]*x^3 +1416486*x^2 +24304*x+1) / ((x^6+x^3+1) *(x^2+x+1)^3 *(x-1)^9).