Number of 8Xn -1,1 arrays such that the sum over i=1..8,j=1..n of i*x(i,j) is zero, the sum of x(i,j) is zero, and rows are nondecreasing (number of ways to distribute n-across galley oarsmen left-right at 8 fore-aft positions so that there are no turning moments on the ship).
A225348
Number of 8Xn -1,1 arrays such that the sum over i=1..8,j=1..n of i*x(i,j) is zero, the sum of x(i,j) is zero, and rows are nondecreasing (number of ways to distribute n-across galley oarsmen left-right at 8 fore-aft positions so that there are no turning moments on the ship).
Terms
- a(0) =8a(1) =77a(2) =410a(3) =1525a(4) =4508a(5) =11291a(6) =25056a(7) =50659a(8) =95130a(9) =168289a(10) =283338a(11) =457627a(12) =713374a(13) =1078615a(14) =1587974a(15) =2283803a(16) =3217102a(17) =4448769a(18) =6050622a(19) =8106883a(20) =10715232a(21) =13988475a(22) =18055740a(23) =23064277a(24) =29180742a(25) =36593245a(26) =45512628a(27) =56174753a(28) =68841880
External references
- oeis: A225348