OFFSET
1,3
FORMULA
a(n) = Sum_{k=1..n} Sum_{j=1..floor(k*n/3)} Sum_{i=j..floor((k*n-j)/2)} 1.
MATHEMATICA
Table[Sum[Sum[Sum[1, {i, j, Floor[(k*n - j)/2]}], {j, Floor[k*n/3]}], {k, n}], {n, 50}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Wesley Ivan Hurt, Apr 05 2021
STATUS
approved