A120889 Triangle read by rows: T(n,k) = gcd(k,ceiling(n/k)) (1 <= k <= n).

1, 1, 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 2, 3, 2, 1, 2, 1, 1, 2, 3, 2, 1, 2, 1, 1, 1, 1, 3, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 2, 1, 1, 1, 2, 1, 2, 1, 2, 1, 1, 2, 1, 1, 1, 2, 1, 2, 1, 2, 1, 1, 1, 1, 1, 4, 1, 3, 1, 2, 1, 2, 1, 2, 1, 1, 1, 1, 4, 1, 3, 1, 2, 1, 2, 1, 2, 1, 1

Offset

1,5

Links

Alois P. Heinz, Rows n = 1..200, flattened

Example

Triangle starts:
  1;
  1, 1;
  1, 2, 1;
  1, 2, 1, 1;
  1, 1, 1, 2, 1;
  1, 1, 1, 2, 1, 1;
  1, 2, 3, 2, 1, 2, 1;
  ...

Maple

T:=proc(n, k) if k<=n then gcd(k, ceil(n/k)) else 0 fi end: for n from 1 to 16 do seq(T(n, k), k=1..n) od; # yields sequence in triangular form # Emeric Deutsch, Jul 26 2006

Mathematica

T[n_, k_] := GCD[k, Ceiling[n/k]];
Table[T[n, k], {n, 1, 16}, {k, 1, n}] // Flatten (* Jean-François Alcover, Feb 10 2021 *)

Crossrefs

Cf. A120888.

Sequence in context: A354614 A192004 A349671 * A322351 A092523 A120891

Adjacent sequences: A120886 A120887 A120888 * A120890 A120891 A120892

Keyword

nonn,tabl

Author

Leroy Quet, Jul 12 2006

Extensions

More terms from Emeric Deutsch, Jul 26 2006

Status

approved