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A047577
Numbers that are congruent to {0, 1, 5, 6, 7} mod 8.
1
0, 1, 5, 6, 7, 8, 9, 13, 14, 15, 16, 17, 21, 22, 23, 24, 25, 29, 30, 31, 32, 33, 37, 38, 39, 40, 41, 45, 46, 47, 48, 49, 53, 54, 55, 56, 57, 61, 62, 63, 64, 65, 69, 70, 71, 72, 73, 77, 78, 79, 80, 81, 85, 86, 87, 88, 89, 93, 94, 95, 96, 97, 101, 102, 103
OFFSET
1,3
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^2*(x^4 + x^3 + x^2 + 4*x + 1)/(x^6 - x^5 - x + 1). (End)
From Wesley Ivan Hurt, Jul 27 2016: (Start)
a(n) = a(n-5) + 8 for n>5.
a(n) = (40*n - 25 + 3*(n mod 5) + 3*((n+1) mod 5) - 12*((n+2) mod 5) + 3*((n+3) mod 5) + 3*((n+4) mod 5))/25.
a(5*k) = 8*k-1, a(5*k-1) = 8*k-2, a(5*k-2) = 8*k-3, a(5*k-3) = 8*k-7, a(5*k-4) = 8*k-8. (End)
MAPLE
A047577:=n->8*floor(n/5)+[0, 1, 5, 6, 7][(n mod 5)+1]: seq(A047577(n), n=0..100); # Wesley Ivan Hurt, Jul 27 2016
MATHEMATICA
Select[Range[0, 100], MemberQ[{0, 1, 5, 6, 7}, Mod[#, 8]] &] (* Wesley Ivan Hurt, Jul 27 2016 *)
PROG
(Magma) [n : n in [0..150] | n mod 8 in [0, 1, 5, 6, 7]]; // Wesley Ivan Hurt, Jul 27 2016
CROSSREFS
Sequence in context: A333532 A121537 A285219 * A293481 A174138 A108401
KEYWORD
nonn,easy
STATUS
approved