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A087642 Sequence of squarefree n such that Q(sqrt(n)) has no element with a fully periodical continued fraction of period 1. 1
3, 6, 7, 11, 14, 15, 19, 21, 22, 23, 30, 31, 33, 34, 35, 38, 39, 42, 43, 46, 47, 51, 55, 57, 59, 62, 66, 67, 69, 70, 71, 77, 78, 79, 83, 86, 87, 91, 93, 94, 95, 102, 103, 105, 107, 110, 111, 114, 115, 118, 119, 123, 127, 129, 131, 133, 134, 138, 139, 141, 142, 143, 146 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,1

COMMENTS

Diophantine equation x^2 - n.y^2 + 4 = 0 has no solution (x,y) for a given squarefree n. Squarefree n not in the sequence A013946. Same sequence with square factors allowed is A087643.

LINKS

Table of n, a(n) for n=3..65.

EXAMPLE

3 is in the sequence because no [k,k,k,k,...] is in Q(sqrt(3))

5 is not in the sequence since Q(sqrt(5)) contains [1,1,1,1,...]

CROSSREFS

Cf. A087643, A013946.

Sequence in context: A214961 A189626 A297292 * A084349 A126003 A047556

Adjacent sequences:  A087639 A087640 A087641 * A087643 A087644 A087645

KEYWORD

easy,nonn

AUTHOR

Thomas Baruchel, Sep 16 2003

STATUS

approved

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Last modified May 19 13:02 EDT 2019. Contains 323393 sequences. (Running on oeis4.)