A091560 Fractional part of e^a(n) is the largest yet.
1, 8, 19, 76, 166, 178, 209, 1907, 20926, 22925, 32653, 119136
Offset: 1
A153711 Minimal exponents m such that the fractional part of Pi^m obtains a maximum (when starting with m=1).
1, 2, 15, 22, 58, 157, 1030, 5269, 145048, 151710
Offset: 1
Comments
Recursive definition: a(1)=1, a(n) = least number m>a(n-1) such that the fractional part of Pi^m is greater than the fractional part of Pi^k for all k, 1<=k
The next such number must be greater than 100000.
a(11) > 300000. - Robert Price, Mar 25 2019
Examples
a(3)=15, since fract(Pi^15)= 0.9693879984..., but fract(Pi^k)<=0.8696... for 1<=k<=14; thus fract(Pi^15)>fract(Pi^k) for 1<=k<15 and 15 is the minimal exponent > 2 with this property.
Crossrefs
Programs
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Mathematica
$MaxExtraPrecision = 100000; p = 0; Select[Range[1, 10000], If[FractionalPart[Pi^#] > p, p = FractionalPart[Pi^#]; True] &] (* Robert Price, Mar 25 2019 *)
Formula
Recursion: a(1):=1, a(k):=min{ m>1 | fract(Pi^m) > fract(Pi^a(k-1))}, where fract(x) = x-floor(x).
Extensions
a(9)-a(10) from Robert Price, Mar 25 2019
A153719 Minimal exponents m such that the fractional part of (Pi-2)^m obtains a maximum (when starting with m=1).
1, 2, 3, 4, 5, 39, 56, 85, 557, 911, 2919, 2921, 4491, 11543, 15724, 98040, 110932, 126659
Offset: 1
Comments
Recursive definition: a(1)=1, a(n) = least number m>a(n-1) such that the fractional part of (Pi-2)^m is greater than the fractional part of (Pi-2)^k for all k, 1<=k
The next such number must be greater than 200000.
a(19) > 300000. - Robert Price, Mar 26 2019
Examples
a(6)=39, since fract((Pi-2)^39)= 0.9586616565..., but fract((Pi-2)^k)<=0.9389018... for 1<=k<=38; thus fract((Pi-2)^39)>fract((Pi-2)^k) for 1<=k<39 and 39 is the minimal exponent > 5 with this property.
Programs
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Mathematica
$MaxExtraPrecision = 100000; p = 0; Select[Range[1, 10000], If[FractionalPart[(Pi - 2)^#] > p, p = FractionalPart[(Pi - 2)^#]; True] &] (* Robert Price, Mar 26 2019 *)
Formula
Recursion: a(1)=1, a(k) = min{ m>1 | fract((Pi-2)^m) > fract((Pi-2)^a(k-1))}, where fract(x) = x-floor(x).
A153699 Greatest number m such that the fractional part of (10/9)^A153695(m) >= 1-(1/m).
1, 1, 1, 2, 3, 8, 15, 264, 334, 465, 683, 713, 758, 8741, 15912, 18920, 38560, 409895
Offset: 1
Examples
a(7)=15, since 1-(1/16)=0.9375>fract((10/9)^A153695(7))=fract((10/9)^13)=0.9341...>=1-(1/15).
Formula
a(n):=floor(1/(1-fract((10/9)^A153695(n)))), where fract(x) = x-floor(x).
A153675 Greatest number m such that the fractional part of (101/100)^A153671(m) >= 1-(1/m).
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 5, 6, 6, 7, 9, 11, 13, 19, 30, 76, 81, 238, 913, 1334, 4645, 6812, 17396, 351085, 552184
Offset: 1
Keywords
Examples
a(5)=1, since 1-(1/2)=0.5>fract((101/100)^A153671(5))=fract((101/100)^5)=0.0510...>=1-(1/1).
Formula
a(n):=floor(1/(1-fract((101/100)^A153671(n)))), where fract(x) = x-floor(x).
A153683 Greatest number m such that the fractional part of (1024/1000)^A153679(m) >= 1-(1/m).
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 4, 5, 6, 9, 17, 93, 123, 1061, 1360, 4137, 66910, 571666, 1192010
Offset: 1
Examples
a(5)=1, since 1-(1/2)=0.5>fract((1024/1000)^A153679(5))=fract((1024/1000)^5)=0.0510...>=1-(1/1).
Formula
a(n):=floor(1/(1-fract((1024/1000)^A153679(n)))), where fract(x) = x-floor(x).
A153691 Greatest number m such that the fractional part of (11/10)^A153687(m) >= 1-(1/m).
1, 1, 1, 1, 2, 4, 19, 21, 28, 151, 200, 709, 767, 5727, 15908, 162819, 302991
Offset: 1
Examples
a(6)=4, since 1-(1/5)=0.8>fract((11/10)^A153687(6))=fract((11/10)^6)=0.771...>=1-(1/4).
Formula
a(n):=floor(1/(1-fract((11/10)^A153687(n)))), where fract(x) = x-floor(x).
A154136 Greatest number m such that the fractional part of (4/3)^A154132(m) >= 1-(1/m).
1, 4, 88, 1228, 2253, 4562, 8183, 167378
Offset: 1
Examples
a(3)=88, since 1-(1/89)=0.988764...>fract((4/3)^A154132(3))=fract((4/3)^8)=0.988721...>0.988636...=1-(1/88).
Formula
a(n):=floor(1/(1-fract((4/3)^A154132(n)))), where fract(x) = x-floor(x).
Comments
Examples
Crossrefs
Programs
Mathematica
PARI
Formula
Extensions