A267747 Numbers k such that k mod 2 = k mod 3 = k mod 5.

0, 1, 30, 31, 60, 61, 90, 91, 120, 121, 150, 151, 180, 181, 210, 211, 240, 241, 270, 271, 300, 301, 330, 331, 360, 361, 390, 391, 420, 421, 450, 451, 480, 481, 510, 511, 540, 541, 570, 571, 600, 601, 630, 631, 660, 661, 690, 691, 720, 721, 750, 751, 780, 781, 810, 811, 840

Offset: 1

Author

Mikk Heidemaa, Jan 20 2016

Keywords

• nonn
• easy

Comments

Numbers k such that k == 0 or 1 (mod 30). - Robert Israel, Jan 20 2016

Links

• Colin Barker, Table of n, a(n) for n = 1..1000
• Index entries for linear recurrences with constant coefficients, signature (1,1,-1).

Crossrefs

Cf. A267711.

Programs

Magma

[15*n-7*(-1)^n-22: n in [1..60]]; // Vincenzo Librandi, Jan 21 2016

Mathematica

Table[15*n - 7*(-1)^n - 22, {n, 1000}] (* Or *)
Select[ Range[0, 20000], (Mod[#, 2]==Mod[#, 3]==Mod[#, 5]) &]
LinearRecurrence[{1,1,-1},{0,1,30},60] (* Harvey P. Dale, Nov 15 2021 *)

PARI

concat(0, Vec(x^2*(29*x+1)/((x-1)^2*(x+1)) + O(x^60))) \\ Colin Barker, Jan 21 2016

Formula

a(n) = 15*n - 7*(-1)^n - 22.

G.f.: x^2*(29*x+1)/((x-1)^2*(x+1)).