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A047512
Numbers that are congruent to {1, 2, 4, 6, 7} mod 8.
1
1, 2, 4, 6, 7, 9, 10, 12, 14, 15, 17, 18, 20, 22, 23, 25, 26, 28, 30, 31, 33, 34, 36, 38, 39, 41, 42, 44, 46, 47, 49, 50, 52, 54, 55, 57, 58, 60, 62, 63, 65, 66, 68, 70, 71, 73, 74, 76, 78, 79, 81, 82, 84, 86, 87, 89, 90, 92, 94, 95, 97, 98, 100, 102, 103
OFFSET
1,2
FORMULA
From Chai Wah Wu, May 30 2016: (Start)
G.f.: x*(x + 1)*(x^2 + 1)^2/((x - 1)^2*(x^4 + x^3 + x^2 + x + 1)).
a(n) = a(n-1) + a(n-5) - a(n-6) for n > 6. (End)
From Wesley Ivan Hurt, Jul 28 2016: (Start)
a(n) = a(n-5) + 8 for n > 5.
a(n) = (40*n - 20 + 3*(n mod 5) - 2*((n+1) mod 5) - 2*((n+2) mod 5) + 3*((n+3) mod 5) - 2*((n+4) mod 5))/25.
a(5k) = 8k-1, a(5k-1) = 8k-2, a(5k-2) = 8k-4, a(5k-3) = 8k-6, a(5k-4) = 8k-7. (End)
MAPLE
A047512:=n->8*floor(n/5)+[(1, 2, 4, 6, 7)][(n mod 5)+1]: seq(A047512(n), n=0..100); # Wesley Ivan Hurt, Jul 28 2016
MATHEMATICA
Select[Range[0, 100], MemberQ[{1, 2, 4, 6, 7}, Mod[#, 8]] &] (* Wesley Ivan Hurt, Jul 28 2016 *)
PROG
(Magma) [n : n in [0..150] | n mod 8 in [1, 2, 4, 6, 7]]; // Wesley Ivan Hurt, Jul 28 2016
(PARI) a(n)=[-1, 1, 2, 4, 6][n%5+1] + n\5*8 \\ Charles R Greathouse IV, Jul 29 2016
CROSSREFS
Sequence in context: A247000 A213356 A079393 * A026273 A184658 A247910
KEYWORD
nonn,easy
STATUS
approved