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A087643 Diophantine equation x^2 - n.y^2 + 4 = 0 has no solution (x,y) for a given n. +0
2
3, 6, 7, 11, 12, 14, 15, 19, 21, 22, 23, 24, 27, 28, 30, 31, 33, 34, 35, 38, 39, 42, 43, 44, 46, 47, 48, 51, 54, 55, 56, 57, 59, 60, 62, 63, 66, 67, 69, 70, 71, 75, 76, 77, 78, 79, 83, 84, 86, 87, 88, 91, 92, 93, 94, 95, 96, 99, 102, 103, 105, 107, 108, 110, 111, 112, 114 (list; graph; listen)
OFFSET

3,1

COMMENT

No quadratic number with a fully periodical continued fraction of period 1 can be written as (a+b.sqrt(n))/c with n allowed to have square factors. Sequence A087642 is the same sequence with only square-free values.

EXAMPLE

The sequence contains 44 because x^2 - 44.y^2 + 4 = 0 has no solution.

CROSSREFS

Cf. A087642.

Adjacent sequences: A087640 A087641 A087642 this_sequence A087644 A087645 A087646

Sequence in context: A051146 A136272 A101184 this_sequence A022544 A091067 A120511

KEYWORD

easy,nonn

AUTHOR

Thomas Baruchel (baruchel(AT)users.sourceforge.net), Sep 16 2003

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Last modified October 15 09:18 EDT 2008. Contains 145015 sequences.


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