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A047603
Numbers that are congruent to {1, 2, 3, 4, 5} mod 8.
1
1, 2, 3, 4, 5, 9, 10, 11, 12, 13, 17, 18, 19, 20, 21, 25, 26, 27, 28, 29, 33, 34, 35, 36, 37, 41, 42, 43, 44, 45, 49, 50, 51, 52, 53, 57, 58, 59, 60, 61, 65, 66, 67, 68, 69, 73, 74, 75, 76, 77, 81, 82, 83, 84, 85, 89, 90, 91, 92, 93, 97, 98, 99, 100, 101
OFFSET
1,2
FORMULA
From Chai Wah Wu, Jun 10 2016: (Start)
a(n) = a(n-1) + a(n-5) - a(n-6) for n > 6.
G.f.: x*(3*x^5 + x^4 + x^3 + x^2 + x + 1)/(x^6 - x^5 - x + 1). (End)
From Wesley Ivan Hurt, Jul 28 2016: (Start)
a(n) = a(n-5) + 8 for n>5.
a(n) = (40*n - 45 + 3*(n mod 5) + 3*((n+1) mod 5) + 3*((n+2) mod 5) + 3*((n+3) mod 5) - 12*((n+4) mod 5))/25.
a(5k) = 8k-3, a(5k-1) = 8k-4, a(5k-2) = 8k-5, a(5k-3) = 8k-6, a(5k-4) = 8k-7. (End)
a(n) = n + 3*floor((n-1)/5). - Wesley Ivan Hurt, Aug 08 2016
MAPLE
A047603:=n->8*floor(n/5)+[(1, 2, 3, 4, 5)][(n mod 5)+1]: seq(A047603(n), n=0..100); # Wesley Ivan Hurt, Jul 28 2016
MATHEMATICA
Select[Range[0, 100], MemberQ[{1, 2, 3, 4, 5}, Mod[#, 8]] &] (* Wesley Ivan Hurt, Jul 28 2016 *)
LinearRecurrence[{1, 0, 0, 0, 1, -1}, {1, 2, 3, 4, 5, 9}, 100] (* Vincenzo Librandi, Aug 08 2016 *)
PROG
(Magma) [n : n in [0..150] | n mod 8 in [1..5]]; // Wesley Ivan Hurt, Jul 28 2016
CROSSREFS
Sequence in context: A119955 A158573 A194398 * A047362 A032969 A095906
KEYWORD
nonn,easy
STATUS
approved