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

Terms

a(0) =5a(1) =35a(2) =154a(3) =504a(4) =1349a(5) =3142a(6) =6575a(7) =12688a(8) =22923a(9) =39266a(10) =64315a(11) =101460a(12) =154942a(13) =230095a(14) =333394a(15) =472735a(16) =657496a(17) =898863a(18) =1209864a(19) =1605777a(20) =2104139a(21) =2725200a(22) =3491939a(23) =4430572a(24) =5570527a(25) =6945053a(26) =8591154a(27) =10550253a(28) =12868125a(29) =15595628