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A293315
The integer k that minimizes |k/2^n - r|, where r = golden ratio.
4
2, 3, 6, 13, 26, 52, 104, 207, 414, 828, 1657, 3314, 6627, 13255, 26510, 53020, 106039, 212079, 424158, 848316, 1696632, 3393263, 6786526, 13573053, 27146106, 54292211, 108584423, 217168846, 434337692, 868675383, 1737350766, 3474701533, 6949403065
OFFSET
0,1
LINKS
FORMULA
a(n) = floor(1/2 + r*2^n), where r = (1+sqrt(5))/2.
a(n) = A293313(n) if (fractional part of r*2^n) < 1/2, else a(n) = A293313(n).
MAPLE
A293315:=n->floor(1/2+2^n*(1+sqrt(5))/2): seq(A293315(n), n=0..40); # Wesley Ivan Hurt, Oct 06 2017
MATHEMATICA
z = 120; r = GoldenRatio;
Table[Floor[r*2^n], {n, 0, z}]; (* A293313 *)
Table[Ceiling[r*2^n], {n, 0, z}]; (* A293314 *)
Table[Round[r*2^n], {n, 0, z}]; (* A293315 *)
PROG
(PARI) a(n) = (2^n*(1+sqrt(5))+1)\2; \\ Altug Alkan, Oct 06 2017
(Magma) [Floor((2^n*(1+Sqrt(5))+1)/2): n in [0..33]]; // Vincenzo Librandi, Oct 08 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Oct 06 2017
STATUS
approved