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

1,2

Comments

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

Links

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

Formula

A000012 * A133080 as infinite lower triangular matrices.

Example

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;
  ...

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 *)

Prog

(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

Crossrefs

Cf. A133080, A000012, A032766.

Sequence in context: A214848 A006338 A020903 * A083921 A119672 A271608

Adjacent sequences: A133080 A133081 A133082 * A133084 A133085 A133086

Keyword

nonn,tabl

Author

Gary W. Adamson, Sep 08 2007

Status

approved