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A047423
Numbers that are congruent to {2, 3, 4, 5, 6} mod 8.
1
2, 3, 4, 5, 6, 10, 11, 12, 13, 14, 18, 19, 20, 21, 22, 26, 27, 28, 29, 30, 34, 35, 36, 37, 38, 42, 43, 44, 45, 46, 50, 51, 52, 53, 54, 58, 59, 60, 61, 62, 66, 67, 68, 69, 70, 74, 75, 76, 77, 78, 82, 83, 84, 85, 86, 90, 91, 92, 93, 94, 98, 99, 100, 101, 102
OFFSET
1,1
FORMULA
a(n+1) = 3*floor(n/5) + n + 2. - Gary Detlefs, Mar 12 2010
G.f.: x*(1+x)*(2*x^4-x^3+2*x^2-x+2) / ( (x^4+x^3+x^2+x+1)*(x-1)^2 ). - R. J. Mathar, Dec 05 2011
From Wesley Ivan Hurt, Aug 03 2016: (Start)
a(n) = a(n-1) + a(n-5) - a(n-6) for n > 6, a(n) = a(n-5) + 8 for n > 5.
a(n) = (8*n + 2 - 3*((n+4) mod 5))/5.
a(5k) = 8k-2, a(5k-1) = 8k-3, a(5k-2) = 8k-4, a(5k-3) = 8k-5, a(5k-4) = 8k-6. (End)
MAPLE
A047423:=n->8*floor(n/5)+[(2, 3, 4, 5, 6)][(n mod 5)+1]: seq(A047423(n), n=0..100); # Wesley Ivan Hurt, Aug 03 2016
MATHEMATICA
Select[Range[0, 100], MemberQ[{2, 3, 4, 5, 6}, Mod[#, 8]] &] (* Wesley Ivan Hurt, Aug 03 2016 *)
PROG
(Magma) [n : n in [0..150] | n mod 8 in [2..6]]; // Wesley Ivan Hurt, Aug 03 2016
CROSSREFS
Sequence in context: A007093 A285469 A302706 * A032970 A137691 A215726
KEYWORD
nonn,easy
STATUS
approved