A047337 Numbers that are congruent to {0, 1, 2, 3, 4} mod 7.

0, 1, 2, 3, 4, 7, 8, 9, 10, 11, 14, 15, 16, 17, 18, 21, 22, 23, 24, 25, 28, 29, 30, 31, 32, 35, 36, 37, 38, 39, 42, 43, 44, 45, 46, 49, 50, 51, 52, 53, 56, 57, 58, 59, 60, 63, 64, 65, 66, 67, 70, 71, 72, 73, 74, 77, 78

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Links

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

Programs

Magma

[n: n in [0..150] | n mod 7 in [0..4]]; // Vincenzo Librandi, May 04 2016

Mathematica

DeleteCases[Range[0,80],?(Mod[#,7]>4&)] (* _Harvey P. Dale, Aug 21 2013 *)

Formula

a(n) = 7*floor((n-1)/5) + ((n-1) mod 5). - Gary Detlefs, Mar 09 2010

G.f.: x^2*(1 + x + x^2 + x^3 + 3*x^4) / ( (1 + x + x^2 + x^3 + x^4)*(x-1)^2 ). - R. J. Mathar, Dec 04 2011

a(n) = floor((7/6)*floor(6*(n-1)/5)). - Bruno Berselli, May 03 2016