OFFSET
0
COMMENTS
The sequence takes only the values 0 and 1 and is periodic with period 30. The sequence was used by Chebyshev to obtain the estimate for the prime counting function 0.92*x/log(x) <= #{primes <= x} <= 1.11*x/log(x), for x sufficiently large.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
H. G. Diamond, Elementary methods in the study of the distribution of prime numbers, Bull. Amer. Math. Soc., Vol.7 (3), 1982.
Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1).
MATHEMATICA
Table[Floor[n] - Floor[n/2] - Floor[n/3] - Floor[n/5] + Floor[n/30], {n, 0, 50}] (* G. C. Greubel, Aug 20 2017 *)
PROG
(PARI) a(n) = n - n\2 - n\3 - n\5 + n\30; \\ Michel Marcus, Jul 25 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Peter Bala, Apr 11 2012
STATUS
approved