A106006 a(n) = [n/2] + [n/3] + [n/5].

0, 0, 1, 2, 3, 4, 6, 6, 7, 8, 10, 10, 12, 12, 13, 15, 16, 16, 18, 18, 20, 21, 22, 22, 24, 25, 26, 27, 28, 28, 31, 31, 32, 33, 34, 35, 37, 37, 38, 39, 41, 41, 43, 43, 44, 46, 47, 47, 49, 49, 51, 52, 53, 53, 55, 56, 57, 58, 59, 59, 62, 62, 63, 64, 65, 66, 68, 68, 69, 70, 72, 72, 74, 74, 75

Offset

0,4

Links

Paolo Xausa, Table of n, a(n) for n = 0..10000

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

Formula

G.f.: x^2*(1-x)*(3*x^6+6*x^5+7*x^4+6*x^3+5*x^2+3*x+1)/((1-x^2)*(1-x^3)*(1-x^5)).

a(n) = k*n + O(1), where k = 31/30. - Charles R Greathouse IV, Dec 04 2013

Mathematica

A106006[n_] := Plus @@ Quotient[n, {2, 3, 5}];
Array[A106006, 100, 0] (* Paolo Xausa, Sep 06 2025 *)

Prog

(PARI) a(n)=n\2+n\3+n\5 \\ Charles R Greathouse IV, Dec 04 2013

Crossrefs

Sequence in context: A060019 A359100 A093451 * A364104 A050460 A379108

Adjacent sequences: A106003 A106004 A106005 * A106007 A106008 A106009

Keyword

nonn,easy

Author

Jonathan Vos Post, Jan 19 2007

Status

approved