A128219 A000012 * A127701. a(1) = 1, a(2) = 2, a(3) = 2; by rows, n-1 terms of 2, 3, 4, ... followed by "n".

1, 2, 2, 2, 3, 3, 2, 3, 4, 4, 2, 3, 4, 5, 5, 2, 3, 4, 5, 6, 6, 2, 3, 4, 5, 6, 7, 7, 2, 3, 4, 5, 6, 7, 8, 8, 2, 3, 4, 5, 6, 7, 8, 9, 9, 2, 3, 4, 5, 6, 7, 8, 9, 10, 10, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 12, 2, 3, 4, 5, 6

Offset

1,2

Links

Table of n, a(n) for n=1..83.

Formula

A000012 * A127701 as infinite lower triangular matrices.

Example

First few rows of the triangle:
  1;
  2, 2;
  2, 3, 3;
  2, 3, 4, 4;
  2, 3, 4, 5, 5;
  2, 3, 4, 5, 6, 6;
  2, 3, 4, 5, 6, 7, 7;
  ...

Mathematica

trm[i_]:=Join[Range[2, i], {i}]; Flatten[Table[trm[n], {n, 13}]] (* Harvey P. Dale, Nov 14 2012 *)

Crossrefs

Cf. A000012, A127701, A034856 (row sums), A128220.

Sequence in context: A094528 A077774 A344150 * A238969 A238956 A331415

Adjacent sequences: A128216 A128217 A128218 * A128220 A128221 A128222

Keyword

nonn,tabl

Author

Gary W. Adamson, Feb 19 2007

Status

approved