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A087446
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Numbers that are congruent to {1, 6} mod 15.
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2
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1, 6, 16, 21, 31, 36, 46, 51, 61, 66, 76, 81, 91, 96, 106, 111, 121, 126, 136, 141, 151, 156, 166, 171, 181, 186, 196, 201, 211, 216, 226, 231, 241, 246, 256, 261, 271, 276, 286, 291, 301, 306, 316, 321, 331, 336, 346, 351, 361, 366, 376, 381, 391, 396, 406
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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LINKS
| Index to sequences with linear recurrences with constant coefficients, signature (1,1,-1)
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FORMULA
| G.f.: x*(1+5*x+9*x^2)/((1+x)*(1-x)^2); E.g.f.: (30x-1)exp(x)/4+5exp(-x)/4; a(n)=(18n-1)/4+5(-1)^n/4.
a(n)=15*n-a(n-1)-23 (with a(1)=1) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Aug 08 2010]
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EXAMPLE
| For n=2, a(2)=15*2-1-23=6; n=3, a(3)=15*3-6-23=16; n=4, a(4)=15*4-16-23=21 [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Aug 08 2010]
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CROSSREFS
| Cf. A001651, A047241, A087444, A087445.
Sequence in context: A104392 A037001 A118139 * A051808 A034053 A199988
Adjacent sequences: A087443 A087444 A087445 * A087447 A087448 A087449
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KEYWORD
| easy,nonn
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Sep 04 2003
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