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A106706
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a(0) = 19; for n>0, successively subtract 5, subtract 3 and double.
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0
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19, 14, 11, 22, 17, 14, 28, 23, 20, 40, 35, 32, 64, 59, 56, 112, 107, 104, 208, 203, 200, 400, 395, 392, 784, 779, 776, 1552, 1547, 1544, 3088, 3083, 3080, 6160, 6155, 6152, 12304, 12299, 12296, 24592, 24587, 24584, 49168, 49163, 49160, 98320, 98315, 98312, 196624
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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COMMENTS
| Suggested by a test found on the Internet.
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LINKS
| Jeffrey N. Shaumeyer, Bearcastle Blog, One Post, Two ...
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FORMULA
| G.f.: (-19*x^5 - 25*x^4 - 35*x^3 + 11*x^2 + 14*x + 19)/[(1 - 2*x^3)*(1 - x^3)).
a(3n) = 3*2^n+16, a(3n+1) = 3*2^n+11, a(3n+2) = 3*2^n+8.
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MAPLE
| f:=proc(n) option remember; if n=0 then RETURN(19); fi; if n mod 3 = 1 then RETURN(f(n-1)-5); elif n mod 3 = 2 then RETURN(f(n-1)-3); else RETURN(2*f(n-1)); fi; end;
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PROG
| (PARI) a(n)=3*2^(n\3)+[16, 11, 8][n%3+1] \\ - M. F. Hasler, Nov 16 2010
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CROSSREFS
| Sequence in context: A177923 A155848 A088399 * A099939 A135734 A109410
Adjacent sequences: A106703 A106704 A106705 * A106707 A106708 A106709
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KEYWORD
| nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), based on correspondence with Jeffrey N. Shaumeyer, Apr 23 2006
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