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A195171
a(n) = 5*n - floor(n*r), where r=(1+sqrt(5))/2 (the golden ratio).
1
0, 4, 7, 11, 14, 17, 21, 24, 28, 31, 34, 38, 41, 44, 48, 51, 55, 58, 61, 65, 68, 72, 75, 78, 82, 85, 88, 92, 95, 99, 102, 105, 109, 112, 115, 119, 122, 126, 129, 132, 136, 139, 143, 146, 149, 153, 156, 159, 163, 166, 170, 173, 176, 180, 183, 187, 190, 193
OFFSET
0,2
LINKS
FORMULA
a(n) = 5*n - A000201(n) = n + A195170(n). - R. J. Mathar, Sep 11 2011
MATHEMATICA
With[{c = GoldenRatio}, Table[5*n - Floor[c*n], {n, 0, 50}]] (* G. C. Greubel, Oct 31 2017 *)
PROG
(Magma) [5*n-Floor(n*(1+Sqrt(5))/2): n in [0..70]]; // Vincenzo Librandi, Sep 11 2011
(PARI) for(n=0, 50, print1(5*n - floor(n*(1+sqrt(5))/2), ", ")) \\ G. C. Greubel, Oct 31 2017
(Python)
from math import isqrt
def A195171(n): return (m:=5*n)-(n+isqrt(n*m)>>1) # Chai Wah Wu, Aug 10 2022
CROSSREFS
Sequence in context: A327737 A081834 A078309 * A184623 A184581 A310725
KEYWORD
nonn
AUTHOR
Clark Kimberling, Sep 10 2011
STATUS
approved