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A191291 The number of bases >=2 in which n is 3-digit number. 2

%I #14 Mar 22 2023 17:41:08

%S 0,0,0,1,1,1,1,0,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,3,3,2,2,2,2,2,2,2,2,

%T 2,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,

%U 4,4,4,4,4,4,4,4,4,4,4,4,5,5

%N The number of bases >=2 in which n is 3-digit number.

%F a(n) = floor(sqrt(n))-floor(n^(1/3)) = A000196(n) - A048766(n).

%t Table[Floor[Sqrt[n]]-Floor[CubeRoot[n]],{n,90}] (* _Harvey P. Dale_, Mar 22 2023 *)

%o (PARI) a(n)=sqrtint(n)-floor((n+.5)^(1/3)) \\ _Charles R Greathouse IV_, Jan 03 2013

%Y Cf. A191279.

%K nonn,easy,base

%O 1,16

%A _Vladimir Shevelev_, May 29 2011

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Last modified April 25 07:53 EDT 2024. Contains 371964 sequences. (Running on oeis4.)