A047497 Numbers that are congruent to {1, 2, 4, 5, 7} mod 8.

1, 2, 4, 5, 7, 9, 10, 12, 13, 15, 17, 18, 20, 21, 23, 25, 26, 28, 29, 31, 33, 34, 36, 37, 39, 41, 42, 44, 45, 47, 49, 50, 52, 53, 55, 57, 58, 60, 61, 63, 65, 66, 68, 69, 71, 73, 74, 76, 77, 79, 81, 82, 84, 85, 87, 89, 90, 92, 93, 95, 97, 98, 100, 101, 103

Offset

1,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..5000

Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,1,-1).

Formula

a(n) = floor((8n-3)/5). [Gary Detlefs, Mar 07 2010]

From R. J. Mathar, Mar 23 2010: (Start)

a(n) = a(n-1) + a(n-5) - a(n-6).

G.f.: x*(1 + x + 2*x^2 + x^3 + 2*x^4 + x^5)/ ((x^4 + x^3 + x^2 + x + 1) * (x-1)^2). (End)

Maple

seq(floor((8*n-3)/5), n=1..56); # Gary Detlefs, Mar 07 2010

Mathematica

Select[Range[120], MemberQ[{1, 2, 4, 5, 7}, Mod[#, 8]]&] (* or *) LinearRecurrence[ {1, 0, 0, 0, 1, -1}, {1, 2, 4, 5, 7, 9}, 100] (* Harvey P. Dale, Jun 05 2017 *)
Table[8 n + {1, 2, 4, 5, 7}, {n, 0, 20}]//Flatten (* Vincenzo Librandi, Jun 06 2017 *)

Prog

(PARI) for (n=1, 80, print1((8*n-3)\5, ", ")) \\ Michel Marcus, Sep 10 2014
(Magma) I:=[1, 2, 4, 5, 7]; [n le 5 select I[n] else Self(n-5) + 8 : n in [1..70]]; // Vincenzo Librandi, Jun 06 2017

Crossrefs

Cf. A047399 (complement).

Sequence in context: A188019 A189382 A087063 * A004956 A026351 A184656

Adjacent sequences: A047494 A047495 A047496 * A047498 A047499 A047500

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved