A121339 Periodic part of continued fraction for square roots of integers.

2, 1, 2, 4, 2, 4, 1, 1, 1, 4, 1, 4, 6, 3, 6, 2, 6, 1, 1, 1, 1, 6, 1, 2, 1, 6, 1, 6, 8, 4, 8, 2, 1, 3, 1, 2, 8, 2, 8, 1, 1, 2, 1, 1, 8, 1, 2, 4, 2, 1, 8, 1, 3, 1, 8, 1, 8, 10, 5, 10, 3, 2, 3, 10, 2, 1, 1, 2, 10, 2, 10, 1, 1, 3, 5, 3, 1, 1, 10, 1, 1, 1, 10, 1, 2, 1, 10, 1, 4, 1, 10, 1, 10, 12, 6, 12, 4, 12

Offset: 2

Author

Franklin T. Adams-Watters, Aug 28 2006

Keywords

• nice
• nonn
• tabf

Examples

			The table starts:
  2
  1 2
  <empty>
  4
  2 4
  1 1 1 4
  1 4
		

Links

• T. D. Noe, Rows n = 2..1000 of triangle, flattened

Crossrefs

Cf. A003285 (row lengths), A013943 (row lengths for nonempty rows).

Programs

Mathematica

a[n_] := If[ IntegerQ[ Sqrt[n] ], {}, ContinuedFraction[ Sqrt[n] ] // Last]; Table[a[n], {n, 2, 39}] // Flatten (* Jean-François Alcover, Sep 10 2012 *)