A085383 Triangle read by rows, 1 <= k <= n: T(n,k) = floor(n/k)*ceiling(n/k).

1, 4, 1, 9, 2, 1, 16, 4, 2, 1, 25, 6, 2, 2, 1, 36, 9, 4, 2, 2, 1, 49, 12, 6, 2, 2, 2, 1, 64, 16, 6, 4, 2, 2, 2, 1, 81, 20, 9, 6, 2, 2, 2, 2, 1, 100, 25, 12, 6, 4, 2, 2, 2, 2, 1, 121, 30, 12, 6, 6, 2, 2, 2, 2, 2, 1, 144, 36, 16, 9, 6, 4, 2, 2, 2, 2, 2, 1, 169, 42, 20, 12, 6, 6, 2, 2, 2, 2, 2, 2

Offset: 1

Author

Reinhard Zumkeller, Aug 12 2003

Keywords

• nonn
• tabl

Comments

T(n,1) = A000290(n);

T(n,2) = A002620(n) for n > 1;

T(n,n) = 1.

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A000290, A002620.

Programs

Mathematica

Table[Floor[n/k]Ceiling[n/k],{n,20},{k,n}]//Flatten (* Harvey P. Dale, Jan 01 2023 *)