OFFSET
1,1
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..10000
FORMULA
From G. C. Greubel, Jan 13 2018: (Start)
A005408: a(n) = n + [n*(sin(Pi/5))^2] + [n*(cos(Pi/5))^2] = 2*n - 1.
A189932: b(n) = n + [n*(csc(Pi/5))^2] + [n*(cot(Pi/5))^2].
A189933: c(n) = n + [n*(sec(Pi/5))^2] + [n*(tan(Pi/5))^2]. (End)
MATHEMATICA
With[{s=Sin[Pi/5]^2, t=Cos[Pi/5]^2}, Table[n+Floor[n/t]+Floor[(n*s)/t], {n, 80}]] (* Harvey P. Dale, Feb 22 2013 *)
PROG
(PARI) for(n=1, 100, print1(n + floor(n/(cos(Pi/5))^2) + floor(n*(tan(Pi/5))^2), ", ")) \\ G. C. Greubel, Jan 13 2018
(Magma) C<i> := ComplexField(); [n + Floor(n/(Cos(Pi(C)/5))^2) + Floor(n*(Tan(Pi(C)/5))^2): n in [1..100]]; // G. C. Greubel, Jan 13 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, May 01 2011
STATUS
approved