OFFSET
1,2
COMMENTS
Numbers n such that 1/4 < {n*phi} < 3/4, where phi is the golden ratio (1+sqrt(5))/2 and { } denotes fractional part. - Burghard Herrmann, Nov 14 2017
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..5500
Burghard Herrmann, Characterization of some golden ratio sequences
Burghard Herrmann, How integer sequences find their way into areas outside pure mathematics, The Fibonacci Quarterly (2019) Vol. 57, No. 5, 67-71.
MATHEMATICA
PROG
(PARI) isok(n) = my(u=(1+sqrt(5))/2); floor(2*n+4*n*u)-floor(n*u)-floor(n+n*u)-floor(n+2*n*u) == 1; \\ Michel Marcus, Nov 14 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, May 06 2011
STATUS
approved