Number of strings of numbers x(i=1..7) in 0..n with sum i*x(i)^2 equal to n*49.

Terms

a(0) =5a(1) =31a(2) =130a(3) =368a(4) =915a(5) =1993a(6) =3818a(7) =6805a(8) =11052a(9) =18352a(10) =28860a(11) =39870a(12) =61568a(13) =88347a(14) =109115a(15) =159804a(16) =215574a(17) =266628a(18) =362832a(19) =445236a(20) =541934a(21) =738893a(22) =903565a(23) =1011760a(24) =1295590a(25) =1650305a(26) =1800585a(27) =2280782a(28) =2748502a(29) =2923138