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
Examples
The square root of 5168 is 71.88880302...
Links
- Harvey P. Dale, Table of n, a(n) for n = 1..630
Programs
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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 *) -
PARI
isA073585(n)=if(issquare(n),0,my(x=sqrt(n));x-=floor(x);x=floor(10000*x);x%1111==0)
Comments