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 1-8 of 8 results.

A067314 Duplicate of A066022.

Original entry on oeis.org

1, 1, 1, 2, 3, 4, 5, 6, 8, 9, 11, 12, 13, 15, 17, 18, 20, 21, 23, 25, 27, 28, 30, 32, 34, 35, 37
Offset: 0

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Author

Keywords

A054382 James Joyce's "Ulysses" sequence: number of digits in n^(n^n).

Original entry on oeis.org

1, 1, 2, 13, 155, 2185, 36306, 695975, 15151336, 369693100, 10000000001, 297121486765, 9622088391635, 337385711567665, 12735782555419983, 515003176870815368, 22212093154093428530, 1017876887958723919835, 49390464231494436119285
Offset: 0

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Author

Antreas P. Hatzipolakis (xpolakis(AT)otenet.gr), May 07 2000

Keywords

Comments

Although Joyce mentions (9^9)^9, he clearly intended to refer to 9^(9^9).
(9^9)^9 is only 196627050475552913618075908526912116283103450944214766927315415537966391196809, whereas 9^(9^9) has 369693100 digits.

Examples

			"Because some years previously in 1886 when occupied with the problem of the quadrature of the circle he had learned of the existence of a number computed to a relative degree of accuracy to be of such magnitude and of so many places, e.g., the 9th power of the 9th power of 9, that, the result having been obtained, 33 closely printed volumes of 1000 pages each of innumerable quires and reams of India paper would have to be requisitioned in order to contain the complete tale of its printed integers of units, tens, hundreds, thousands, tens of thousands, hundreds of thousands, millions, tens of millions, hundreds of millions, billions, the nucleus of the nebula of every digit of every series containing succinctly the potentiality of being raised to the utmost kinetic elaboration of any power of any of its powers." - James Joyce, Ulysses, Chapter 17.
a(2)=2 since 2^(2^2)=2^4=16 has 2 digits. - _Carmine Suriano_, Feb 01 2011
a(0)=1 because 0^(0^0)=0^1=0, which has 1 digit. - _T. D. Noe_, Feb 01 2011
		

References

  • C. A. Laisant (1906) proved that the number of digits of a(9), 9^9^9, is 369693100. H. S. Uhler (1947) published the log of the number to 250 decimal places.
  • David Wells: The Penguin Dictionary of Curious and Interesting Numbers. Penguin Books, 1986, p. 208.

Crossrefs

Programs

  • Maple
    A055642 := proc(n) max(1,ilog10(n)+1) ; end proc:
    A054382 := proc(n) A055642(n^(n^n)) ; end proc: # R. J. Mathar, Feb 01 2011
  • Mathematica
    f[ j_ ] := 1 + Floor[ Log[10, j] j^j ]; Table[ f[j], {j, 2, 20} ]

Formula

a(n) = floor(n^n*log_10(n)) + 1 for n > 0. - Jianing Song, Nov 21 2018

Extensions

More terms from Michael Kleber, May 07 2000

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

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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

A095703 Integer part of the (positive) solution to x^x = 10^n.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 7, 8, 9, 10, 10, 11, 12, 12, 13, 13, 14, 15, 15, 16, 17, 17, 18, 18, 19, 19, 20, 21, 21, 22, 22, 23, 23, 24, 25, 25, 26, 26, 27, 27, 28, 28, 29, 29, 30, 30, 31, 31, 32, 32, 33, 33, 34, 34, 35, 35, 36, 36, 37, 37, 38, 38, 39, 39, 40, 40, 41, 41
Offset: 0

Views

Author

Cino Hilliard, Jul 06 2004

Keywords

Crossrefs

Programs

  • Maple
    a:= n-> `if`(n=0, 1, (t-> floor(t/LambertW(t)))(n*log(10))):
    seq(a(n), n=0..80);  # Alois P. Heinz, Nov 07 2019
  • PARI
    a(n) = floor(solve(x=1, max(10,n+1), x^x-10^n))
    
  • PARI
    a(n) = {my(k=1); while(k^k <= 10^n, k++); k-1} \\ Andrew Howroyd, Nov 07 2019

Formula

a(n) = n*log(10)/LambertW(n*log(10)) for n > 0, a(0) = 1. - Alois P. Heinz, Nov 07 2019

Extensions

Terms a(23) and beyond from Andrew Howroyd, Nov 07 2019

A330192 Integers k such that the length of decimal expansion of k^k is a repdigit.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 35, 46, 51, 194, 234, 273, 349, 386, 423, 1411, 1717, 2017, 2889, 3173, 13455, 22933, 68896, 89733, 130334, 169949, 189481, 208861, 1273968, 4977354, 12523569, 43631177, 123579653, 631296394, 21506946847, 3541615362849, 8590606646469
Offset: 1

Views

Author

Michel Marcus, Dec 05 2019

Keywords

Comments

Integers k such that A066022(k) belongs to A010785.

Examples

			For k=1 to 9, k^k has k digits, that is, A066022(k) is a repdigit.
k=631296394 is a term since k^k has 5555555555 digits. See Cobeli link.
		

Crossrefs

Cf. A010785 (repdigits), A000312 (n^n), A066022 (number of digits of n^n), A330193.

Programs

  • Mathematica
    Flatten@ Reap[Sow[0]; Do[v = d (10^nd-1)/9; s = Solve[v-1 <= x Log10[x] < v, x, Integers]; If[s != {}, Sow[x /. s]], {nd, 15}, {d, 9}]][[2, 1]] (* Giovanni Resta, Dec 05 2019 *)
  • PARI
    isok(k) = #Set(digits(#Str(k^k))) == 1;

Extensions

a(28)-a(42) from Giovanni Resta, Dec 05 2019

A330193 a(n) is the length of the decimal expansion of A330192(n)^A330192(n).

Original entry on oeis.org

1, 1, 1, 2, 3, 4, 5, 6, 8, 9, 11, 55, 77, 88, 444, 555, 666, 888, 999, 1111, 4444, 5555, 6666, 9999, 11111, 55555, 99999, 333333, 444444, 666666, 888888, 999999, 1111111, 7777777, 33333333, 88888888, 333333333, 999999999, 5555555555, 222222222222, 44444444444444
Offset: 1

Views

Author

Michel Marcus, Dec 05 2019

Keywords

Crossrefs

Cf. A010785 (repdigits), A000312 (n^n), A055642, A066022, A330192.

Programs

  • Mathematica
    Flatten@ Reap[Sow[1]; Do[v = d (10^nd - 1)/9; s = Solve[v-1 <= x Log10[x] < v, x, Integers]; If[s != {}, Sow[v /. s]], {nd, 15}, {d, 9}]][[2, 1]] (* Giovanni Resta, Dec 05 2019 *)

Formula

a(n) = A066022(A330192(n)).
a(n) = A055642(A330192(n)^A330192(n)).

Extensions

a(28)-a(41) from Giovanni Resta, Dec 05 2019

A327603 Number of digits in (n^n)^(n^n).

Original entry on oeis.org

1, 1, 3, 39, 617, 10922, 217833, 4871823, 121210687, 3327237897, 100000000001, 3268336354411, 115465060699617, 4386014250379643, 178300955775879752, 7725047653062230514, 355393490465494856466, 17303907095298306637188, 889028356166899850147118
Offset: 0

Views

Author

Natan Arie Consigli, Sep 22 2019

Keywords

Comments

a(0) = 1 whether we take 0^0 = 1 or 0^0 = 0.
The standard simplification of (n^n)^(n^n) is n^(n^(n+1)). - M. F. Hasler, Oct 15 2019

Examples

			a(10) = 1 + floor(10^(10+1) * log_10(10)) = 1 + floor( 100000000000 * 1) = 100000000001.
a(10^3) = 3*10^3003 + 1.
		

Crossrefs

Programs

  • Mathematica
    Table[IntegerLength[(n^n)^(n^n)], {n, 1, 8}] (* Human friendly *)
    Table[1 + Floor[n^(n + 1) * Log10[n]], {n, 1, 16}] (* Computationally efficient *)
  • PARI
    a(n) = my(x=n^n); 1 + floor(x*log(x)/log(10));
    
  • PARI
    A327603(n,L=log(10))=n^(n+1)*log(n)\L+1 \\ Supplying the 2nd arg allows to avoid re-computation of log(10) on each call, and also to get the number of digits in any desired base. - M. F. Hasler, Oct 15 2019

Formula

a(n) = 1 + floor(n^(n+1) * log_10(n)).
a(10^k) = k * 10^(k*(10^k + 1)) + 1. - Jon E. Schoenfield, Sep 29 2019
a(n) = A055642(A004217(n)), n > 0. - Felix Fröhlich, Oct 15 2019

Extensions

a(9)-a(15) from Nathaniel Johnston, Sep 23 2019
a(13)-a(15) corrected and a(16) appended by Natan Arie Consigli, Sep 25 2019
a(17)-a(18) from Jon E. Schoenfield, Sep 29 2019

A259368 Number of digits in n^n when written in binary.

Original entry on oeis.org

1, 3, 5, 9, 12, 16, 20, 25, 29, 34, 39, 44, 49, 54, 59, 65, 70, 76, 81, 87, 93, 99, 105, 111, 117, 123, 129, 135, 141, 148, 154, 161, 167, 173, 180, 187, 193, 200, 207, 213, 220, 227, 234, 241, 248, 255, 262, 269, 276, 283, 290, 297, 304, 311, 318, 326, 333
Offset: 1

Views

Author

Adam J.T. Partridge, Jun 25 2015

Keywords

Examples

			For n=3, 3^3=11011_2 so a(3)=5.
		

Crossrefs

Programs

  • Magma
    [Floor(n*Log(n)/Log(2)) + 1: n in [1..70]]; // Vincenzo Librandi, Jul 15 2015
  • Mathematica
    Array[IntegerLength[#^#, 2] &, 60] (* or *)
    Array[Floor[# Log[2, #]] + 1 &, 60] (* Michael De Vlieger, Jul 03 2015 *)
  • PARI
    a(n) = #binary(n^n); \\ Michel Marcus, Jul 03 2015
    

Formula

a(n) = floor(n*log(n)/log(2)) + 1.
a(n) = A070939(A000312(n)). - Michel Marcus, Jul 03 2015
Showing 1-8 of 8 results.