1,2

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

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

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

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

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

nonn

Reinhard Zumkeller, Jul 02 2002

approved