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A047256
Numbers that are congruent to {0, 1, 2, 3, 5} mod 6.
2
0, 1, 2, 3, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 23, 24, 25, 26, 27, 29, 30, 31, 32, 33, 35, 36, 37, 38, 39, 41, 42, 43, 44, 45, 47, 48, 49, 50, 51, 53, 54, 55, 56, 57, 59, 60, 61, 62, 63, 65, 66, 67, 68, 69, 71, 72, 73, 74, 75, 77, 78, 79
OFFSET
1,3
FORMULA
G.f.: x^2*(1+x)*(x^3 + x^2 + 1) / ( (x^4 + x^3 + x^2 + x + 1)*(x-1)^2 ). - R. J. Mathar, Oct 08 2011
Sum_{n>=2} (-1)^n/a(n) = (3-2*sqrt(3))*Pi/36 + log(2+sqrt(3))/sqrt(3). - Amiram Eldar, Dec 17 2021
a(n) = n + floor(n/5) - 1. - Aaron J Grech, Oct 03 2024
MATHEMATICA
Flatten[# + {0, 1, 2, 3, 5} & /@ (6 Range[0, 11])] (* or *)
Select[Range[0, 67], MemberQ[{0, 1, 2, 3, 5}, Mod[#, 6]] &] (* Robert G. Wilson v, Sep 26 2016 *)
LinearRecurrence[{1, 0, 0, 0, 1, -1}, {0, 1, 2, 3, 5, 6}, 60] (* Harvey P. Dale, Jul 20 2020 *)
CROSSREFS
Cf. A047226.
Sequence in context: A183570 A181092 A184526 * A039252 A332484 A360556
KEYWORD
nonn,easy
STATUS
approved