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A096493 Number of distinct primes in continued fraction period of square root of n. 3
0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0, 1, 0, 0, 0, 0, 2, 1, 1, 1, 1, 0, 0, 0, 1, 2, 1, 1, 2, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 1, 1, 2, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 2, 1, 2, 0, 0, 0, 0, 0, 3, 0, 1, 1, 2, 1, 1, 0, 0, 2, 2, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 1, 1, 1, 0, 3, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,19

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

EXAMPLE

n=127: the period={3,1,2,2,7,11,7,2,2,1,3,22},

distinct-primes={2,3,7,11}, so a[127]=4;

MATHEMATICA

{te=Table[0, {m}], u=1}; Do[s=Count[PrimeQ[Union[Last[ContinuedFraction[n^(1/2)]]]], True]; te[[u]]=s; u=u+1, {n, 1, m}]; te

dpcf[n_]:=Module[{s=Sqrt[n]}, If[IntegerQ[s], 0, Count[Union[ ContinuedFraction[ s][[2]]], _?PrimeQ]]]; Array[dpcf, 110] (* Harvey P. Dale, Mar 18 2016 *)

CROSSREFS

Cf. A003285, A013646, A096491, A096492.

Sequence in context: A244250 A167230 A093658 * A269242 A076882 A229745

Adjacent sequences:  A096490 A096491 A096492 * A096494 A096495 A096496

KEYWORD

nonn

AUTHOR

Labos Elemer, Jun 29 2004

STATUS

approved

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Last modified August 17 06:56 EDT 2018. Contains 313810 sequences. (Running on oeis4.)