A133083 A000012 * A133080.

1, 2, 1, 2, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 1

Offset: 1

Author

Gary W. Adamson, Sep 08 2007

Keywords

• nonn
• tabl

Comments

Row sums = A032766, congruent to {0,1} (mod 3): (1, 3, 4, 6, 7, 9, 10, ...).

Examples

			First few rows of the triangle:
  1;
  2, 1;
  2, 1, 1;
  2, 1, 2, 1;
  2, 1, 2, 1, 1;
  2, 1, 2, 1, 2, 1;
  ...
		

Links

• G. C. Greubel, Table of n, a(n) for the first 50 rows, flattened

Crossrefs

Cf. A133080, A000012, A032766.

Programs

Mathematica

T[n_, k_] := If[k == n, 1, 1  + (1 - (-1)^k)/2 ]; Table[T[n, k], {n, 1, 10}, {k, 1, n}] (* G. C. Greubel, Oct 21 2017 *)

PARI

for(n=1,10, for(k=1,n, print1(if(k==n, 1, 1 + (1-(-1)^k)/2), ", "))) \\ G. C. Greubel, Oct 21 2017

Formula

A000012 * A133080 as infinite lower triangular matrices.