cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-10 of 11 results. Next

A241299 Initial digit of the decimal expansion of n^(n^n) or n^^3 (in Don Knuth's up-arrow notation).

Original entry on oeis.org

0, 1, 1, 7, 1, 1, 2, 3, 6, 4, 1, 3, 4, 6, 1, 3, 1, 3, 1, 1, 3, 2, 3, 5, 5, 2, 2, 2, 8, 1, 1, 9, 1, 2, 3, 4, 8, 2, 4, 1, 1, 2, 8, 3, 2, 1, 4, 2, 5, 1, 6, 7, 2, 2, 2, 2, 2, 2, 8, 4, 1, 4, 8, 1, 5, 8, 4, 1, 4, 1, 2, 1, 9, 6, 6, 2, 1, 1, 7, 6, 1, 7, 7, 2, 4, 1, 8, 6, 1, 7, 1, 1, 3, 1, 2, 6, 3, 5, 1, 1, 1, 2, 2, 5, 4
Offset: 0

Views

Author

Keywords

Comments

0^^3 = 0 since 0^^k = 1 for even k, 0 for odd k, k >= 0.
Conjecture: the distribution of the initial digits obey Zipf's law.
The distribution of the first 1000 terms beginning with 1: 302, 196, 124, 91, 72, 46, 71, 53, 45.

Examples

			a(0) = 0, a(1) = 1, a(2) = 1 because 2^(2^2) = 16, a(3) = 7 because 3^(3^3) = 7625597484987 and its initial digit is 7, etc.
		

Crossrefs

Programs

  • Mathematica
    g[n_] := Quotient[n^p, 10^(Floor[ p*Log10@ n] - (1004 + p))]; f[n_] := Block[{p = n}, Quotient[ Nest[ g@ # &, p, p], 10^(1004 + p)]]; Array[f, 105, 0]

Formula

For n > 0, a(n) = floor(t/10^floor(log_10(t))) where t = n^(n^n).
a(n) = A000030(A002488(n)). - Omar E. Pol, Jul 04 2019

A241293 Decimal expansion of 4^(4^(4^4)) = 4^^4.

Original entry on oeis.org

2, 3, 6, 1, 0, 2, 2, 6, 7, 1, 4, 5, 9, 7, 3, 1, 3, 2, 0, 6, 8, 7, 7, 0, 2, 7, 4, 9, 7, 7, 8, 1, 7, 9, 4, 3, 0, 9, 4, 6, 1, 2, 7, 2, 9, 1, 4, 7, 7, 5, 1, 5, 4, 4, 6, 7, 1, 9, 2, 5, 6, 9, 4, 6, 2, 1, 2, 7, 1, 1, 8, 5, 3, 6, 6, 6, 4, 7, 5, 5, 2, 4, 9, 4, 5, 7, 6, 9, 3, 5, 0, 1, 0, 1, 9, 4, 1, 9, 9, 7, 7, 1, 6, 1, 6
Offset: 1

Views

Author

Keywords

Comments

The offset is 1 because the true offset would be 8.072304726...*10^153, which is too large to be represented properly in the OEIS.
This is the decimal expansion of 2^2^513. - Jianing Song, Dec 25 2018

Examples

			2361022671459731320687702749778179430946127291477515446719256946212711853666475524945769350101941997...(8.072304726...*10^153) ... 7470426497333490366540651560537534642789067586985427238232605843019607448189676936860456095261392896.
The above line shows the first one hundred decimal digits and the last one hundred digits with the number of unrepresented digits in parenthesis.
The final one hundred digits where computed by: PowerMod[4, 4^4^4, 10^100].
		

Crossrefs

Programs

  • Mathematica
    nbrdgt = 105; f[base_, exp_] := RealDigits[ 10^FractionalPart[ N[ exp*Log10[ base], nbrdgt + Floor[ Log10[ exp]] + 2]], 10, nbrdgt][[1]]; f[ 4, 4^4^4] (* or *)
    p = 4; f[n_] := Quotient[n^p, 10^(Floor[p * Log10@ n] - (1004 + p^p))]; IntegerDigits@ Quotient[ Nest[ f@ # &, p, p^p], 10^(900 + p^p)] (* Program fixed by Jianing Song, Sep 18 2019 *)

Formula

4^(4^(4^4)) = ((((( ... 245 ... (((((4^4)^4)^4)^4)^4) ... 245 ... ^4)^4)^4)^4)^4)^4.

Extensions

Keyword: fini added by Jianing Song, Sep 18 2019

A241291 Decimal expansion of 2^(2^(2^(2^(2^2)))) = 2^^6.

Original entry on oeis.org

2, 1, 2, 0, 0, 3, 8, 7, 2, 8, 8, 0, 8, 2, 1, 1, 9, 8, 4, 8, 8, 5, 1, 6, 4, 6, 9, 1, 6, 6, 2, 2, 7, 4, 6, 3, 0, 8, 3, 5, 6, 5, 4, 2, 3, 0, 6, 7, 5, 3, 7, 2, 4, 8, 3, 6, 2, 5, 9, 5, 1, 7, 5, 2, 3, 5, 4, 4, 1, 4, 5, 6, 5, 5, 6, 1, 1, 6, 1, 0, 4, 0, 7, 0, 8, 7, 7, 1, 0, 0, 8, 8, 0, 6, 9, 3, 2, 2, 1, 3, 9, 7, 3, 7, 3
Offset: 1

Views

Author

Keywords

Comments

The offset is 1 because the true offset would be 6.0312260626165015 * 10^19727, which is too large to be represented properly in the OEIS.
2^0 = 1, 2^1 = 2, 2^2 = 4,
2^2^2 = 2^^3 = (2^2)^2 = 16,
2^2^2^2 = 2^^4 = (((2^2)^2)^2)^2 = 65536,
2^(2^(2^(2^2))) = 2^^5 = (((((((((((((((2^2)^2)^2)^2)^2)^2)^2)^2)^2)^2)^2)^2)^2)^2)^2)^2 =
2003529930406846464979072351560255750447825475569751419265016973710894059556311453089506130880933348...(19529 digits)...9087575630505718260979581044520267611188489786293085833548068862693010305614986891826277507437428736.

Examples

			2120038728808211984885164691662274630835654230675372483625951752354414565561161040708771008806932213...(10^(6.0312260626165015 * 10^19727))...9087575630505718260979581044520267611188489786293085833548068862693010305614986891826277507437428736.
The above example line shows the first one hundred decimal digits and the last one hundred digits with the number of unrepresented digits in parentheses.
		

Crossrefs

Programs

  • Mathematica
    nbrdgt = 105; f[base_, exp_] := RealDigits[ 10^FractionalPart[ N[ exp*Log10[ base], nbrdgt + Floor[ Log10[ exp]] + 2]], 10, nbrdgt][[1]]; f[2, 2^2^2^2^2]

Formula

Equals 2^2^2^2^2^2 = 2^^6.

Extensions

Keyword: fini added by Jianing Song, Sep 18 2019

A241292 Decimal expansion of 3^(3^(3^3)) = 3^^4.

Original entry on oeis.org

1, 2, 5, 8, 0, 1, 4, 2, 9, 0, 6, 2, 7, 4, 9, 1, 3, 1, 7, 8, 6, 0, 3, 9, 0, 6, 9, 8, 2, 0, 3, 2, 8, 1, 2, 1, 5, 5, 1, 8, 0, 4, 6, 7, 1, 4, 3, 1, 6, 5, 9, 6, 0, 1, 5, 1, 8, 9, 6, 7, 4, 9, 4, 4, 3, 8, 1, 2, 1, 1, 0, 1, 1, 3, 0, 0, 0, 1, 7, 7, 8, 5, 3, 1, 0, 8, 0, 3, 9, 0, 3, 2, 9, 6, 2, 4, 0, 1, 1, 5, 6, 9, 5, 8, 5
Offset: 3638334640025

Views

Author

Keywords

Comments

Decimal expansion of 3^7625597484987. - Jianing Song, Sep 15 2019

Examples

			=1258014290627491317860390698203281215518046714316596015189674944381211011300017785310803903296240115...(3638334639825)...5344828628021555146929939999502212249640012905650177570718344711077047886315075206738945776100739387.
The above example line shows the first one hundred decimal digits and the last one hundred digits with the number of unrepresented digits in parenthesis.
The final one hundred digits where computed by: PowerMod[3, 3^3^3, 10^100].
		

Crossrefs

Programs

  • Mathematica
    nbrdgt = 105; f[base_, exp_] := RealDigits[ 10^FractionalPart[ N[ exp*Log10[ base], nbrdgt + Floor[ Log10[ exp]] + 2]], 10, nbrdgt][[1]]; f[ 3, 3^3^3] (* or *)
    p = 3; f[n_] := Quotient[n^p, 10^(Floor[p * Log10@ n] - (1004 + p^p))]; IntegerDigits@ Quotient[ Nest[ f@ # &, p, p^p], 10^(900 + p^p)]
  • PARI
    3.^3^3^3 \\ Charles R Greathouse IV, Apr 25 2016

Formula

= 3^(3^(3^3)) = ((((( ... 16 ... (((((3^3)^3)^3)^3)^3) ... 16 ... ^3)^3)^3)^3)^3)^3.

Extensions

Keyword: fini added by Jianing Song, Sep 18 2019

A241295 Decimal expansion of 6^(6^(6^6)) = 6^^4.

Original entry on oeis.org

4, 4, 4, 6, 2, 3, 5, 1, 9, 0, 2, 3, 6, 9, 3, 4, 6, 9, 7, 5, 2, 5, 6, 5, 8, 2, 2, 2, 8, 2, 9, 2, 0, 0, 1, 5, 4, 0, 5, 7, 9, 4, 1, 4, 5, 4, 2, 4, 6, 3, 9, 6, 6, 3, 4, 2, 7, 8, 2, 6, 1, 5, 6, 9, 4, 4, 6, 3, 1, 4, 6, 6, 9, 7, 2, 3, 2, 2, 9, 7, 7, 5, 8, 4, 9, 2, 9, 4, 3, 0, 5, 0, 4, 8, 2, 1, 9, 1, 9, 3, 2, 6, 3, 7, 4
Offset: 1

Views

Author

Keywords

Comments

The offset is 1 because the true offset would be 2.069197376... * 10^36305, which is too large to be represented properly in the OEIS.

Examples

			4446235190236934697525658222829200154057941454246396634278261569446314669723229775849294305048219193...(2.069197376... * 10^36305)...1753131067593004473155552781300975310520790674421755277191077815819279193580406457883859420138438656.
The above line shows the first one hundred decimal digits and the last one hundred digits with the number of unrepresented digits in parenthesis.
The final one hundred digits where computed by: PowerMod[6, 6^6^6, 10^100].
		

Crossrefs

Programs

  • Mathematica
    nbrdgt = 105; f[base_, exp_] := RealDigits[ 10^FractionalPart[ N[ exp*Log10[ base], nbrdgt + Floor[ Log10[ exp]] + 2]], 10, nbrdgt][[1]]; f[ 6, 6^6^6] (* Program fixed by Jianing Song, Sep 18 2019 *)

Formula

6^(6^(6^6)) = ((((( ... 46645 ... (((((6^6)^6)^6)^6)^6) ... 46645 ... ^6)^6)^6)^6)^6)^6.

Extensions

Keyword: fini added by Jianing Song, Sep 18 2019

A241296 Decimal expansion of 7^(7^(7^7)) = 7^^4.

Original entry on oeis.org

7, 8, 3, 3, 0, 0, 5, 2, 3, 7, 4, 8, 0, 0, 5, 5, 5, 6, 5, 4, 0, 3, 8, 5, 4, 0, 9, 4, 7, 5, 4, 6, 5, 3, 0, 8, 2, 9, 1, 9, 0, 4, 4, 3, 9, 8, 5, 5, 8, 7, 7, 0, 1, 3, 1, 4, 8, 2, 1, 1, 9, 7, 0, 3, 1, 8, 5, 0, 2, 8, 4, 3, 6, 3, 3, 9, 7, 2, 6, 3, 4, 4, 4, 4, 2, 9, 7, 2, 3, 3, 8, 2, 8, 9, 4, 1, 0, 0, 4, 5, 1, 7, 7, 8, 7
Offset: 1

Views

Author

Keywords

Comments

The offset is 1 because the true offset would be 3.177419493... * 10^695974, which is too large to be represented properly in the OEIS.

Examples

			7833005237480055565403854094754653082919044398558770131482119703185028436339726344442972338289410045...(3.177419493... * 10^695974)...1766659134033863120639301828875443004447501140571853058472378511366058254036038182879357182733172343.
The above line shows the first one hundred decimal digits and the last one hundred digits with the number of unrepresented digits in parenthesis.
The final one hundred digits where computed by: PowerMod[7, 7^7^7, 10^100].
		

Crossrefs

Programs

  • Mathematica
    nbrdgt = 105; f[base_, exp_] := RealDigits[ 10^FractionalPart[ N[ exp*Log10[ base], nbrdgt + Floor[ Log10[ exp]] + 2]], 10, nbrdgt][[1]]; f[ 7, 7^7^7]

Formula

7^(7^(7^7)) = ((((( ... 823532 ... (((((7^7)^7)^7)^7)^7) ... 823532 ... ^7)^7)^7)^7)^7)^7.

Extensions

Keyword: fini added by Jianing Song, Sep 18 2019

A241297 Decimal expansion of 8^(8^(8^8)) = 8^^4.

Original entry on oeis.org

6, 4, 7, 4, 0, 3, 2, 9, 6, 4, 6, 6, 9, 7, 0, 6, 7, 9, 9, 7, 3, 8, 6, 6, 2, 5, 1, 7, 9, 3, 9, 0, 2, 7, 4, 9, 3, 5, 5, 2, 4, 6, 5, 7, 8, 1, 5, 5, 6, 6, 0, 5, 4, 7, 1, 6, 8, 1, 8, 4, 5, 3, 5, 6, 3, 8, 7, 4, 9, 0, 9, 6, 9, 9, 4, 7, 6, 4, 5, 1, 3, 0, 3, 8, 6, 9, 6, 9, 9, 3, 2, 8, 2, 3, 7, 1, 4, 0, 2, 1, 4, 4, 3, 0, 5
Offset: 1

Views

Author

Keywords

Comments

The offset is 1 because the true offset would be 5.431653469... * 10^15151335, which is too large to be represented properly in the OEIS.
Decimal expansion of 2^(3*2^50331648). - Jianing Song, Dec 26 2022

Examples

			=6474032964669706799738662517939027493552465781556605471681845356387490969947645130386969932823714021...(5.431653456330093... * 10^15151335)...6641744766927456476257727570637041060682921214560194830819153337200429887920249826536946437619449856.
The above example line shows the first one hundred decimal digits and the last one hundred digits with the number of unrepresented digits in parenthesis.
The final one hundred digits where computed by: PowerMod[8, 8^8^8, 10^100].
		

Crossrefs

Programs

  • Mathematica
    nbrdgt = 105; f[base_, exp_] := RealDigits[ 10^FractionalPart[ N[ exp*Log10[ base], nbrdgt + Floor[ Log10[ exp]] + 2]], 10, nbrdgt][[1]]; f[ 8, 8^8^8]

Formula

= 8^(8^(8^8)) = ((((( ... 16777205 ... (((((8^8)^8)^8)^8)^8) ... 16777205 ... ^8)^8)^8)^8)^8)^8.

Extensions

Keyword: fini added by Jianing Song, Sep 18 2019

A241298 Decimal expansion of 9^(9^9) = 9^^3.

Original entry on oeis.org

4, 2, 8, 1, 2, 4, 7, 7, 3, 1, 7, 5, 7, 4, 7, 0, 4, 8, 0, 3, 6, 9, 8, 7, 1, 1, 5, 9, 3, 0, 5, 6, 3, 5, 2, 1, 3, 3, 9, 0, 5, 5, 4, 8, 2, 2, 4, 1, 4, 4, 3, 5, 1, 4, 1, 7, 4, 7, 5, 3, 7, 2, 3, 0, 5, 3, 5, 2, 3, 8, 8, 7, 4, 7, 1, 7, 3, 5, 0, 4, 8, 3, 5, 3, 1, 9, 3, 6, 6, 5, 2, 9, 9, 4, 3, 2, 0, 3, 3, 3, 7, 5, 0, 6, 0
Offset: 369693100

Views

Author

Keywords

Comments

Decimal expansion of 3^774840978. - Jianing Song, Sep 15 2019

Examples

			= 42812477317574704803698711593056352133905548224144
  35141747537230535238874717350483531936652994320333
  ... (369,692,900 digits omitted) ...
  26170043150602250406601961656994397543610268552663
  74036682906190174923494324178799359681422627177289.
The first and last 100 digits are shown above, with the intervening digits omitted.
The final one hundred digits were computed using PowerMod[9, 9^9, 10^100].
		

References

  • Ilan Vardi, "Computational Recreations in Mathematica," Addison-Wesley Publishing Co., Redwood City, CA, 1991, pages 226-229.

Crossrefs

Programs

  • Mathematica
    nbrdgt = 105; f[base_, exp_] := RealDigits[ 10^FractionalPart[ N[ exp*Log10[ base], nbrdgt + Floor[ Log10[ exp]] + 2]], 10, nbrdgt][[1]]; f[9, 9^9] (* or *)
    f[n_] := Quotient[n^9, 10^(Floor[9*Log10@ n] - 1010)]; Nest[ f@ # &, 9, 9]

Formula

9^(9^9) = ((((((((9^9)^9)^9)^9)^9)^9)^9)^9)^9.

Extensions

Keyword: fini added by Jianing Song, Sep 18 2019

A243913 Decimal expansion of 9^(9^(9^9)) = 9^^4.

Original entry on oeis.org

2, 1, 4, 1, 9, 8, 3, 2, 9, 4, 7, 9, 6, 8, 0, 5, 6, 1, 1, 3, 3, 3, 3, 6, 4, 3, 7, 3, 4, 4, 2, 4, 8, 0, 8, 3, 0, 1, 4, 7, 2, 2, 7, 0, 7, 2, 8, 4, 5, 1, 2, 8, 4, 8, 8, 7, 0, 6, 5, 1, 6, 1, 9, 5, 9, 8, 2, 8, 0, 8, 7, 4, 9, 6, 5, 6, 7, 0, 4, 8, 4, 7, 0, 3, 6, 1, 1, 8, 4, 4, 7, 2, 4, 9, 9, 1, 7, 3, 6, 8, 5, 3, 4, 8, 8
Offset: 1

Views

Author

Keywords

Comments

The offset is taken to be 1 because the true offset would be 4.085349171835445 * 10^369693099, too large to be written out in full.

Examples

			=2141983294796805611333364373442480830147227072845128488706516195982808749656704847036118447249917368...(4.085349171835445... * 10^369693099) ... 3771540670946945552331518959254852001991324340257630363975097419408973491530163140828233401045865289.
The first and last 100 digits are shown above, with the intervening digits omitted. The final one hundred digits cannot be computed with: PowerMod[9, 9^9^9, 10^100] with any version of Mathematica before version 9. Instead (* Import Mmca coding for "SuperPowerMod" and "LogStar" from text file and then *) SuperPowerMod[9, 4, 10^100].
		

References

  • Ilan Vardi, "Computational Recreations in Mathematica," Addison-Wesley Publishing Co., Redwood City, CA, 1991, pages 226-229.

Crossrefs

Programs

  • Mathematica
    nbrdgt = 105; f[base_, exp_] := RealDigits[ 10^FractionalPart[ N[ exp*Log10[ base], nbrdgt + Floor[ Log10[ exp]] + 2]], 10, nbrdgt][[1]]; f[ 9, 9^9^9] (* needs version 9.0 to run *)

Formula

9^(9^(9^9)) = ((((( ... 387420478 ... (((((9^9)^9)^9)^9)^9) ... 387420478 ... ^9)^9)^9)^9)^9)^9.

Extensions

Keyword: fini added by Jianing Song, Sep 18 2019

A244059 Initial digit of the decimal expansion of n^(n^(n^n)) or n^^4 (in Don Knuth's up-arrow notation).

Original entry on oeis.org

1, 1, 6, 1, 2, 1, 4, 7, 6, 2, 1
Offset: 0

Views

Author

Keywords

Comments

This sequence can also be written as (n↑↑4) in Knuth up-arrow notation.
0^^4 = 1 since 0^^k = 1 for even k, 0 for odd k, k >= 0.
Conjecture: the distribution of the initial digits obey G. K. Zipf's law.

Examples

			a(4)=2 because A241293(1)=2.
		

Crossrefs

Programs

Showing 1-10 of 11 results. Next