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A072689 Difference between (least square >= n) and (largest square <= n). 1
0, 3, 3, 0, 5, 5, 5, 5, 0, 7, 7, 7, 7, 7, 7, 0, 9, 9, 9, 9, 9, 9, 9, 9, 0, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 0, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 0, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 0, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n)=0 iff n is a square.

LINKS

Table of n, a(n) for n=1..78.

FORMULA

a(n) = A057427(n - A048760(n)) * (A000196(A048760(n))*2 + 1).

MATHEMATICA

ds[n_]:=Module[{s=Sqrt[n]}, If[IntegerQ[s], 0, 1+2Floor[s]]]; Array[ds, 80] (* Harvey P. Dale, Dec 05 2013 *)

CROSSREFS

a(n) = A048761(n) - A048760(n).

Cf. A000290, A072690.

Sequence in context: A217552 A128046 A102899 * A021972 A193451 A244492

Adjacent sequences:  A072686 A072687 A072688 * A072690 A072691 A072692

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Jul 02 2002

STATUS

approved

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Last modified October 24 08:42 EDT 2014. Contains 248516 sequences.