A256244 a(n) = sqrt(n + 2*A256243(n)).

3, 2, 3, 4, 3, 4, 3, 4, 5, 4, 5, 4, 5, 4, 5, 6, 5, 6, 5, 6, 5, 6, 5, 6, 7, 6, 7, 6, 7, 6, 7, 6, 7, 6, 7, 8, 7, 8, 7, 8, 7, 8, 7, 8, 7, 8, 7, 8, 9, 8, 9, 8, 9, 8, 9, 8, 9, 8, 9, 8, 9, 8, 9, 10, 9, 10, 9, 10, 9, 10, 9, 10, 9, 10, 9, 10, 9, 10, 9, 10, 11, 10, 11, 10, 11, 10, 11, 10, 11, 10, 11, 10, 11, 10, 11, 10, 11, 10, 11, 12

Offset

1,1

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Formula

sqrt(n) < a(n) <= sqrt(n) + 2. - Charles R Greathouse IV, Mar 23 2015

Mathematica

Table[m = 1; While[! IntegerQ[Sqrt[n + 2*m]], m++]; Sqrt[n + 2 m], {n, 100}] (* Michael De Vlieger, Mar 20 2015 *)

Prog

(PARI) a(n)=m=1; while(!issquare(n+2*m), m++); sqrt(n+2*m)
vector(100, n, round(a(n))) \\ Derek Orr, Mar 22 2015
(PARI) a(n)=my(s=sqrtint(n)); if((s-n)%2, s+1, s+2) \\ Charles R Greathouse IV, Mar 23 2015

Crossrefs

Cf. A000196, A256243.

Sequence in context: A217287 A322200 A028292 * A233386 A093407 A349351

Adjacent sequences: A256241 A256242 A256243 * A256245 A256246 A256247

Keyword

nonn,easy

Author

Zak Seidov, Mar 20 2015

Status

approved