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Search: id:A082871
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| A082871 |
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First component x of pairs (x,y) where x <= y and x!+y! is a square, sorted on x. |
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+0
2
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OFFSET
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1,8
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COMMENT
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Conjecture: the only solutions for x!+y!=n^2 (x <= y) are x=0,0,0,1,1,1,2,4 and y=4,5,7,4,5,7,2,5 respectively.
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PROGRAM
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(PARI) sumfactsq(n) = { for(x=0, n, for(y=1, n, z = x!+y!; if(issquare(z), print1(x" ")) ) ) }
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CROSSREFS
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Cf. A151819.
Adjacent sequences: A082868 A082869 A082870 this_sequence A082872 A082873 A082874
Sequence in context: A128668 A038537 A120313 this_sequence A139627 A166926 A028573
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KEYWORD
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nonn
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AUTHOR
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Cino Hilliard (hillcino368(AT)gmail.com), May 25 2003
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EXTENSIONS
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Edited and corrected by Farideh Firoozbakht (f.firoozbakht(AT)sci.ui.ac.ir), Jul 07 2009
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