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A047385
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Numbers that are congruent to {2, 5} mod 7.
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1
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2, 5, 9, 12, 16, 19, 23, 26, 30, 33, 37, 40, 44, 47, 51, 54, 58, 61, 65, 68, 72, 75, 79, 82, 86, 89, 93, 96, 100, 103, 107, 110, 114, 117, 121, 124, 128, 131, 135, 138, 142, 145, 149, 152, 156, 159, 163, 166, 170
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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LINKS
| Index to sequences with linear recurrences with constant coefficients, signature (1,1,-1).
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FORMULA
| a(n)=7*n-a(n-1)-7, n>1. [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Aug 05 2010]
G.f. x*(2+3*x+2*x^2) / ( (1+x)*(x-1)^2 ). - R. J. Mathar, Dec 05 2011
a(n) = (14*n-(-1)^n-7)/4. - Bruno Berselli, Dec 05 2011
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PROG
| (PARI) a(n)=(14*n-6)>>2 \\ Charles R Greathouse IV, Dec 05 2011
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CROSSREFS
| Sequence in context: A184922 A189461 A190506 * A086814 A086343 A056549
Adjacent sequences: A047382 A047383 A047384 * A047386 A047387 A047388
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KEYWORD
| nonn,easy
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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