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Search: id:A047218
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| A047218 |
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Numbers that are congruent to {0, 3} mod 5. |
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+0
2
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| 0, 3, 5, 8, 10, 13, 15, 18, 20, 23, 25, 28, 30, 33, 35, 38, 40, 43, 45, 48, 50, 53, 55, 58, 60, 63, 65, 68, 70, 73, 75, 78, 80, 83, 85, 88, 90, 93, 95, 98, 100, 103, 105, 108, 110, 113, 115, 118, 120, 123, 125, 128
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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Except for the first term, numbers n such that 36*n^2+72*n+35 is not (p*(p+2)) (p=prime) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Dec 02 2009]
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FORMULA
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a(n) = 2n-5 + ceiling(n/2) - Jesus De Loera (deloera(AT)math.ucdavis.edu)
a(n)=5*n-a(n-1)-7 (with a(1)=0) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Nov 22 2009]
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EXAMPLE
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For n=2, a(2)=5*2-0-7=3; n=3, a(3)=5*3-3-7=5; n=4, a(4)=5*4-5-7=8 [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Nov 22 2009]
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CROSSREFS
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Sequence in context: A079527 A033033 A080754 this_sequence A029919 A094227 A085225
Adjacent sequences: A047215 A047216 A047217 this_sequence A047219 A047220 A047221
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KEYWORD
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nonn,new
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com).
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