This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A261905 Numbers n with property that there is no number k in the range ceiling(sqrt(3n)) <= k <= floor(sqrt(4n)) with k == n mod 2. 0
 1, 2, 5, 6, 8, 9, 11, 14, 17, 19, 22, 24, 29, 34, 41 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Cauchy showed that this list is complete [see Dickson]. REFERENCES L. E. Dickson, History of the Theory of Numbers, Vol. II, Chelsea NY 1992, see pages 18 and 284. LINKS MAPLE # Maple program that verifies that there are no other terms below 100 ans:=[]; for n from 1 to 100 do t1:=ceil(sqrt(3*n)); t2:=floor(sqrt(4*n)); sw:=1;    for i from t1 to t2 do if n-i mod 2 = 0 then sw:=-1; fi; od: if sw=1 then ans:=[op(ans), n]; fi; od: ans; CROSSREFS Sequence in context: A049636 A045573 A161152 * A273867 A047325 A102611 Adjacent sequences:  A261902 A261903 A261904 * A261906 A261907 A261908 KEYWORD nonn,fini,full AUTHOR N. J. A. Sloane, Sep 09 2015 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified April 19 18:33 EDT 2019. Contains 322284 sequences. (Running on oeis4.)