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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

Table of n, a(n) for n=1..15.

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

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