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A189927 b(n) = n + [n*r/s] + [n*t/s]; r=1, s=sin(Pi/5), t=cos(Pi/5), where [] denotes the floor function. 3
3, 7, 12, 15, 19, 24, 27, 32, 36, 40, 44, 48, 52, 56, 60, 65, 68, 72, 77, 81, 84, 89, 93, 97, 101, 105, 109, 113, 117, 122, 125, 130, 134, 137, 142, 146, 149, 154, 158, 163, 166, 170, 175, 178, 182, 187, 190, 195, 199, 203, 207, 211, 215, 219, 223, 228 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..10000

FORMULA

A189926:  a(n) = n + [n*sin(pi/5)] + [n*cos(Pi/5)].

A189927:  b(n) = n + [n*csc(pi/5)] + [n*cot(Pi/5)].

A189928:  c(n) = n + [n*sec(pi/5)] + [n*tan(Pi/5)].

MATHEMATICA

r=1; s=Sin[Pi/5]; t=Cos[Pi/5];

a[n_] := n + Floor[n*s/r] + Floor[n*t/r];

b[n_] := n + Floor[n*r/s] + Floor[n*t/s];

c[n_] := n + Floor[n*r/t] + Floor[n*s/t];

Table[a[n], {n, 1, 120}]  (* A189926 *)

Table[b[n], {n, 1, 120}]  (* A189927 *)

Table[c[n], {n, 1, 120}]  (* A189928 *)

PROG

(PARI) for(n=1, 100, print1(n + floor(n/sin(Pi/5)) + floor(n/tan(Pi/5)), ", ")) \\ G. C. Greubel, Jan 13 2018

(MAGMA) C<i> := ComplexField(); [n + Floor(n/Sin(Pi(C)/5)) + Floor(n/Tan(Pi(C)/5)): n in [1..100]]; // G. C. Greubel, Jan 13 2018

CROSSREFS

Cf. A189926, A189928.

Sequence in context: A310228 A310229 A083031 * A189403 A022805 A310230

Adjacent sequences:  A189924 A189925 A189926 * A189928 A189929 A189930

KEYWORD

nonn

AUTHOR

Clark Kimberling, May 01 2011

STATUS

approved

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Last modified August 10 08:35 EDT 2020. Contains 336368 sequences. (Running on oeis4.)