A189927 - OEIS

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, 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

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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];