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Search: id:A092464
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| A092464 |
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Numbers n congruent to 4 or 9 mod 13. |
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+0
2
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| 4, 9, 17, 22, 30, 35, 43, 48, 56, 61, 69, 74, 82, 87, 95, 100, 108, 113, 121, 126, 134, 139, 147, 152, 160, 165, 173, 178, 186, 191, 199, 204, 212, 217, 225, 230, 238, 243, 251, 256, 264, 269, 277, 282, 290, 295, 303, 308, 316, 321, 329, 334, 342, 347, 355, 360
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OFFSET
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1,1
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COMMENT
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Numbers n such that n^2 is congruent to 3 (modulo 13).
Except for the first term, a(n)=13*n-a(n-1), (with a(1)=9) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Oct 18 2009]
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FORMULA
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a(n)=a(n-2)+13 = a(n-1)+a(n-2)-a(n-3) = 13*n/2-13/4-3*(-1)^n/4. G.f.: x*(4+5*x+4*x^2)/((1+x)*(x-1)^2). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 20 2009]
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CROSSREFS
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A0127547 is a subsequence.
Sequence in context: A082920 A110979 A073173 this_sequence A161320 A134578 A009851
Adjacent sequences: A092461 A092462 A092463 this_sequence A092465 A092466 A092467
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KEYWORD
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nonn
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AUTHOR
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Jun Mizuki (suzuki32(AT)sanken.osaka-u.ac.jp), Mar 25 2004
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EXTENSIONS
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More terms from Ray Chandler (rayjchandler(AT)sbcglobal.net), Mar 27 2004
Edited by N. J. A. Sloane (njas(AT)research.att.com), May 10 2007
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