a(n) = Sum_{l=1..n} Sum_{k=1..l} Sum_{j=1..k} Sum_{i=1..j} (l*k*j*i)^2.
A353021
a(n) = Sum_{l=1..n} Sum_{k=1..l} Sum_{j=1..k} Sum_{i=1..j} (l*k*j*i)^2.
Terms
- a(0) =0a(1) =1a(2) =341a(3) =13013a(4) =196053a(5) =1733303a(6) =10787231a(7) =52253971a(8) =209609235a(9) =725520510a(10) =2230238010a(11) =6217887390a(12) =15973440990a(13) =38276304066a(14) =86383520146a(15) =185042663146a(16) =378620563178a(17) =743881306623
External references
- oeis: A353021