

A047299


Numbers that are congruent to {0, 1, 3, 4, 6} mod 7.


4



0, 1, 3, 4, 6, 7, 8, 10, 11, 13, 14, 15, 17, 18, 20, 21, 22, 24, 25, 27, 28, 29, 31, 32, 34, 35, 36, 38, 39, 41, 42, 43, 45, 46, 48, 49, 50, 52, 53, 55, 56, 57, 59, 60, 62, 63, 64, 66, 67, 69, 70, 71, 73, 74, 76, 77, 78
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OFFSET

1,3


COMMENTS

Nonnegative m such that floor(k*m^2/7) = k*floor(m^2/7), where k = 2 or 3. [Bruno Berselli, Dec 03 2015]
For k > 1 (A007530(k+1)  A007530(k))/30 is a term in this sequence.  Hugo Pfoertner, May 29 2020


LINKS

Table of n, a(n) for n=1..57.
Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,1,1).


FORMULA

G.f.: x^2*(1+2*x+x^2+2*x^3+x^4) / ( (x^4+x^3+x^2+x+1)*(x1)^2 ).  R. J. Mathar, Oct 25 2011
a(n) = floor((7n5)/5).  Lorenz H. Menke, Jr., Jun 19 2013


MATHEMATICA

a[n_]:=Floor[(7n5)/5]; Table[a[i], {i, 1, 30}]; (* Lorenz H. Menke, Jr., Jun 19 2013 *)


PROG

(PARI) a(n)=(7*n5)\5 \\ Charles R Greathouse IV, Jun 19 2013
(Magma) [Floor((7*n5)/5): n in [1..100]]; // Zaki Khandaker, Jun 21 2015


CROSSREFS

Cf. A007530 (prime quadruples).
Sequence in context: A247987 A062975 A276218 * A186159 A184578 A022846
Adjacent sequences: A047296 A047297 A047298 * A047300 A047301 A047302


KEYWORD

nonn,easy


AUTHOR

N. J. A. Sloane


EXTENSIONS

Formula and programs adapted to offset 1 by Michel Marcus, May 30 2020


STATUS

approved



