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]
LINKS
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)*(x-1)^2 ). - R. J. Mathar, Oct 25 2011
a(n) = floor((7n-5)/5). - Lorenz H. Menke, Jr., Jun 19 2013
MATHEMATICA
a[n_]:=Floor[(7n-5)/5]; Table[a[i], {i, 1, 30}]; (* Lorenz H. Menke, Jr., Jun 19 2013 *)
PROG
(PARI) a(n)=(7*n-5)\5 \\ Charles R Greathouse IV, Jun 19 2013
(Magma) [Floor((7*n-5)/5): n in [1..100]]; // Zaki Khandaker, Jun 21 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
Formula and programs adapted to offset 1 by Michel Marcus, May 30 2020
STATUS
approved