A166931 Numbers n with property that n mod k is k-1 for all k = 2..9.

2519, 5039, 7559, 10079, 12599, 15119, 17639, 20159, 22679, 25199, 27719, 30239, 32759, 35279, 37799, 40319, 42839, 45359, 47879, 50399, 52919, 55439, 57959, 60479, 62999, 65519, 68039, 70559, 73079, 75599, 78119, 80639, 83159, 85679

Offset: 1

Author

Luc Comeau-Montasse, Oct 23 2009

Keywords

• nonn
• easy

Links

• G. C. Greubel, Table of n, a(n) for n = 1..1000
• Index entries for linear recurrences with constant coefficients, signature (2, -1).

Programs

Maple

isA166931 := proc(n) for k from 2 to 9 do if n mod k <> k-1 then return false; end if; end do; true; end proc: for n from 1 to 500000 do if isA166931(n) then printf("%d,",n) ; end if; end do ; # R. J. Mathar, Nov 02 2009

Mathematica

Select[Range[90000],And@@Table[Mod[#,k]==k-1,{k,2,9}]&] (* Harvey P. Dale, Jun 14 2011 *)
LinearRecurrence[{2, -1}, {2519, 5039}, 50] (* G. C. Greubel, May 28 2016 *)

Formula

a(n) = 2519 + n*2520.

From G. C. Greubel, May 28 2016: (Start)

a(n) = 2*a(n-1) - a(n-2).

G.f.: (2519 + x)/(1-x)^2.

E.g.f.: (2519 + 2520*x)*exp(x). (End)

Extensions

Edited by N. J. A. Sloane, Oct 25 2009