A330408 Table of A(n,k) read by antidiagonals, where A(1,k)=k; A(n,k) is the least multiple of n >= A(n-1,k).

1, 2, 2, 3, 2, 3, 4, 4, 3, 4, 5, 4, 6, 4, 5, 6, 6, 6, 8, 5, 6, 7, 6, 6, 8, 10, 6, 7, 8, 8, 6, 8, 10, 12, 7, 8, 9, 8, 9, 8, 10, 12, 14, 8, 9, 10, 10, 9, 12, 10, 12, 14, 16, 9, 10, 11, 10, 12, 12, 15, 12, 14, 16, 18, 10, 11, 12, 12, 12, 12, 15, 18, 14, 16, 18, 20

Offset

1,2

Comments

The main diagonal is conjectured to be A166447.

Links

Table of n, a(n) for n=1..76.

Example

Table begins:
  1, 2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, ...
  2, 2,  4,  4,  6,  6,  8,  8, 10, 10, 12, 12, 14, 14, 16, ...
  3, 3,  6,  6,  6,  6,  9,  9, 12, 12, 12, 12, 15, 15, 18, ...
  4, 4,  8,  8,  8,  8, 12, 12, 12, 12, 12, 12, 16, 16, 20, ...
  5, 5, 10, 10, 10, 10, 15, 15, 15, 15, 15, 15, 20, 20, 20, ...
  6, 6, 12, 12, 12, 12, 18, 18, 18, 18, 18, 18, 24, 24, 24, ...
  7, 7, 14, 14, 14, 14, 21, 21, 21, 21, 21, 21, 28, 28, 28, ...
  8, 8, 16, 16, 16, 16, 24, 24, 24, 24, 24, 24, 32, 32, 32, ...
  9, 9, 18, 18, 18, 18, 27, 27, 27, 27, 27, 27, 36, 36, 36, ...

Mathematica

A[1, k_] := A[1, k] = k; A[n_, k_] := A[n, k] = Module[{m = 1}, While[m*n < A[n - 1, k], m++]; m*n]; Table[A[n - k + 1, k], {n, 1, 12}, {k, n, 1, -1}] // Flatten (* Amiram Eldar, Jan 03 2020 *)

Crossrefs

Cf. A166447.

Sequence in context: A123229 A127095 A249871 * A074712 A271914 A087735

Adjacent sequences: A330405 A330406 A330407 * A330409 A330410 A330411

Keyword

nonn,tabl

Author

Ali Sada, Dec 13 2019

Status

approved