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A047218
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Numbers that are congruent to {0, 3} mod 5.
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23
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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, 130, 133, 135, 138, 140, 143, 145, 148
(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
| 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), Aug 05 2010]
Contribution by Bruno Berselli, Jun 28 2011: (Start)
G.f.: (2*x+3)*x^2/((x+1)*(x-1)^2).
a(n) = (10*n+(-1)^n-9)/4.
a(n) = a(n-1)+a(n-2)-a(n-3). (End)
a(n+1)= Sum_k>=0 {A030308(n,k)*b(k)} with b(0)=3 and b(k)=A020714(k-1)=5*2^(k-1) for k>0. - From DELEHAM Philippe, Oct 17 2011.
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EXAMPLE
| 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), Aug 05 2010]
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MATHEMATICA
| Select[Range[0, 200], MemberQ[{0, 3}, Mod[#, 5]] &] (* From Vladimir Joseph Stephan Orlovsky, Feb 12 2012 *)
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PROG
| (PARI) forstep(n=0, 200, [3, 2], print1(n", ")) \\ Charles R Greathouse IV, Oct 17 2011
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CROSSREFS
| Cf. A047211, A047212, A047216
Sequence in context: A080754 A198083 A195168 * A029919 A094227 A085225
Adjacent sequences: A047215 A047216 A047217 * A047219 A047220 A047221
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KEYWORD
| nonn,easy,changed
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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