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A047240 Numbers that are congruent to {0, 1, 2} mod 6. 10
0, 1, 2, 6, 7, 8, 12, 13, 14, 18, 19, 20, 24, 25, 26, 30, 31, 32, 36, 37, 38, 42, 43, 44, 48, 49, 50, 54, 55, 56, 60, 61, 62, 66, 67, 68, 72, 73, 74, 78, 79, 80, 84, 85, 86, 90, 91, 92, 96, 97, 98, 102, 103, 104, 108, 109, 110, 114, 115, 116, 120, 121, 122 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Partial sums of 0,1,1,4,1,1,4,... - Paul Barry, Feb 19 2007

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..10000

FORMULA

G.f.: x(1+x+4x^2)/((1-x)(1-x^3)); a(n)=cos(2*pi*n/3)+sqrt(3)*sin(2*pi*n/3)/3+2n-1; - Paul Barry, Feb 19 2007

a(n)=n-1 + 3*floor((n-1)/3) . [From Philippe DELEHAM, Apr 21 2009]

a(n)=6*floor(n/3) + (n mod 3) [From Gary Detlefs, Mar 09 2010]

a(n+1)=sum_k>=0 {A030341(n,k)*b(k)} with b(0)=1 and b(k)=2*3^k for k>0. - From Philippe Deléham, Oct 22 2011.

MATHEMATICA

Select[Range[0, 200], Mod[#, 6] == 0 || Mod[#, 6] == 1 || Mod[#, 6] == 2 &] (* From Vladimir Joseph Stephan Orlovsky, Jul 07 2011 *)

PROG

(MAGMA) [0], [6*Floor(n/3) + (n mod 3): n in [1..65]]; // Vincenzo Librandi, Oct 23 2011

CROSSREFS

Cf. A047234, A047242.

Sequence in context: A190212 A031198 A201819 * A080333 A194369 A039592

Adjacent sequences:  A047237 A047238 A047239 * A047241 A047242 A047243

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Paul Barry, Feb 19 2007

STATUS

approved

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Last modified May 23 12:38 EDT 2013. Contains 225587 sequences.