A087642 - OEIS

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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.

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

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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: A189626 A338066 A297292 * A084349 A126003 A047556

Adjacent sequences: A087639 A087640 A087641 * A087643 A087644 A087645

KEYWORD

easy,nonn

AUTHOR

Thomas Baruchel, Sep 16 2003

STATUS

approved