Number of distinct solutions of sum{i=1..7}(x(2i-1)*x(2i)) = 0 (mod n), with x() only in 1..n-1.
A180778
Number of distinct solutions of sum{i=1..7}(x(2i-1)*x(2i)) = 0 (mod n), with x() only in 1..n-1.
Terms
- a(0) =0a(1) =0a(2) =9a(3) =198a(4) =2294a(5) =19467a(6) =126864a(7) =674922a(8) =2997717a(9) =11615754a(10) =39660995a(11) =123162204a(12) =348412638a(13) =920581314a(14) =2264397902a(15) =5294830516a(16) =11692554408a(17) =24858751383a(18) =50403391227a(19) =99282023930a(20) =187902783369a(21) =347689331443a(22) =621482071507
External references
- oeis: A180778