A073585 Square root of n has the same nonzero digit in each of the first 4 places to the right of the decimal point.

5168, 6543, 8080, 9779, 11640, 13663, 15848, 18195, 20704, 23375, 26208, 29203, 32360, 35679, 39160, 42803, 46608, 50575, 51731, 54704, 55906, 58995, 60243, 63448, 64742, 68063, 69403, 72840, 74226, 77779, 79211, 81542, 82880, 84358, 86763, 88143, 89667

Offset

1,1

Comments

For each term given, the repeated digit is either 8 or 4.

Links

Harvey P. Dale, Table of n, a(n) for n = 1..630

Example

The square root of 5168 is 71.88880302...

Mathematica

re[n_] := Union[First[RealDigits[Sqrt[n], 10, 4, -1]]]; t = {}; Do[If[Length[x = re[n]] == 1 && x != {0}, AppendTo[t, n]], {n, 90000}]; t (* Jayanta Basu, Jul 02 2013 *)
snd4Q[n_]:=Module[{rd=RealDigits[Sqrt[n], 10, 20], d4}, d4=Take[ Drop[ rd[[1]], rd[[2]]], 4]; d4[[1]]!=0&&Union[Differences[d4]]=={0}]; Select[ Range[100000], snd4Q] (* Harvey P. Dale, Jul 22 2016 *)

Prog

(PARI) isA073585(n)=if(issquare(n), 0, my(x=sqrt(n)); x-=floor(x); x=floor(10000*x); x%1111==0)

Crossrefs

Sequence in context: A251679 A151628 A210400 * A249841 A247258 A107344

Adjacent sequences: A073582 A073583 A073584 * A073586 A073587 A073588

Keyword

nonn,base

Author

Paul Lusch, Aug 28 2002

Status

approved