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 1-5 of 5 results.

A004777 Numbers not congruent to 7 mod 8.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 8, 9, 10, 11, 12, 13, 14, 16, 17, 18, 19, 20, 21, 22, 24, 25, 26, 27, 28, 29, 30, 32, 33, 34, 35, 36, 37, 38, 40, 41, 42, 43, 44, 45, 46, 48, 49, 50, 51, 52, 53, 54, 56, 57, 58, 59, 60, 61, 62, 64, 65, 66, 67, 68, 69, 70, 72, 73, 74, 75, 76, 77
Offset: 1

Views

Author

Keywords

Comments

Numbers that are congruent to {0, 1, 2, 3, 4, 5, 6} mod 8.
Numbers n such that binary expansion does not end 111.
Complement of A004771. - Michel Marcus, Sep 11 2015

Crossrefs

Programs

Formula

G.f.: x^2*(1+x+x^2+x^3+x^4+x^5+2*x^6) / ((x^6+x^5+x^4+x^3+x^2+x+1)*(x-1)^2). - R. J. Mathar, Oct 08 2011
a(n) = floor((n-1)*8/7). - M. F. Hasler, Nov 02 2013
From Wesley Ivan Hurt, Sep 11 2015: (Start)
a(n) = a(n-1) + a(n-7) - a(n-8) for n>8.
a(n) = n - 1 + A132270(n). (End)
From Wesley Ivan Hurt, Jul 20 2016: (Start)
a(n) = (56*n - 77 + (n mod 7) + ((n+1) mod 7) + ((n+2) mod 7) + ((n+3) mod 7) + ((n+4) mod 7) + ((n+5) mod 7) - 6*((n+6) mod 7))/49.
a(7k) = 8k-2, a(7k-1) = 8k-3, a(7k-2) = 8k-4, a(7k-3) = 8k-5, a(7k-4) = 8k-6, a(7k-5) = 8k-7, a(7k-6) = 8k-8. (End)

Extensions

Edited by N. J. A. Sloane Aug 31 2009 at the suggestion of R. J. Mathar.

A059562 Beatty sequence for log(Pi)/(log(Pi)-1).

Original entry on oeis.org

7, 15, 23, 31, 39, 47, 55, 63, 71, 79, 87, 94, 102, 110, 118, 126, 134, 142, 150, 158, 166, 174, 181, 189, 197, 205, 213, 221, 229, 237, 245, 253, 261, 268, 276, 284, 292, 300, 308, 316, 324, 332, 340, 348, 355, 363, 371, 379, 387, 395, 403, 411, 419, 427
Offset: 1

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Author

Mitch Harris, Jan 22 2001

Keywords

Crossrefs

Beatty complement is A059561.
Cf. A053510.

Programs

  • Mathematica
    Floor[Range[100]*(1 + 1/(Log[Pi] - 1))] (* Paolo Xausa, Jul 05 2024 *)
  • PARI
    { default(realprecision, 100); b=log(Pi)/(log(Pi) - 1); for (n = 1, 2000, write("b059562.txt", n, " ", floor(n*b)); ) } \\ Harry J. Smith, Jun 28 2009
    
  • PARI
    A059562(n,c=1-1/log(Pi))=n\c \\ Use \pXX to set sufficiently large precision. - M. F. Hasler, Oct 06 2014

Formula

a(n) = floor(n*(1 + 1/(A053510 - 1))). - Paolo Xausa, Jul 05 2024

A022932 a(n) is the number of powers Pi^m between e^n and e^(n+1).

Original entry on oeis.org

0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1
Offset: 0

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Author

Keywords

Comments

Characteristic function of A059561. - Antti Karttunen, Sep 22 2017

Crossrefs

Cf. A059562 (positions of zeros after the initial a(0)=0), A059561 (of ones).

Programs

  • Mathematica
    t = Table[IntegerPart[i/Log[Pi]] - IntegerPart[(i - 1)/Log[Pi]], {i, 1000000}]; (* Hans Havermann, Sep 22 2017 *)
  • PARI
    a(n)=(n+1)\log(Pi) - n\log(Pi) \\ Charles R Greathouse IV, Jan 16 2017

Extensions

More terms from Antti Karttunen, Sep 22 2017

A022931 Number of e^m between Pi^n and Pi^(n+1).

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1
Offset: 0

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Author

Keywords

Examples

			Pi^5 = 306.01968478528145326274131... and Pi^6 = 961.389193575304437...; in between them we find e^6 = 403.4287934927351226... and no other powers of e with integer exponents. Hence a(5) = 1.
Pi^6 = 961.389193575304437... and Pi^7 = 3020.2932277767920675142...; in between them we find e^7 = 1096.63315842845859926372... and e^8 = 2980.957987041728274743592... Hence a(6) = 2.
		

Crossrefs

Cf. A000796 (Pi), A001113 (e), A053510 (log(Pi)), A059561 (floor(n*log(Pi))).

Programs

  • Maple
    Digits:= 30:
    log_Pi:= evalf(log(Pi));
    a:= n-> floor((n+1)*log_Pi) -floor(n*log_Pi):
    seq(a(n), n=0..80);  # Alois P. Heinz, Dec 21 2018
  • Mathematica
    Table[Floor[(n + 1)Log[Pi]] - Floor[n Log[Pi]], {n, 0, 99}] (* Alonso del Arte, Dec 21 2018 *)
  • Scala
    val logPi = Math.log(Math.PI); for (n <- 0 to 99) yield (Math.floor(logPi  * (n + 1)) - Math.floor(logPi * n)).toInt // Alonso del Arte, Dec 21 2018

Formula

a(n) = floor((n + 1) log Pi) - floor(n log Pi). - Alonso del Arte, Dec 20 2018

A249329 First row of spectral array W(log(Pi)).

Original entry on oeis.org

1, 7, 8, 55, 62, 435, 497, 3440, 3937, 27208, 31145, 215199, 246344, 1702099, 1948443, 13462620
Offset: 1

Views

Author

Colin Barker, Dec 03 2014

Keywords

Comments

log(Pi) = 1.144729885849400174143427351353058711647294812915311571513623...
The sequence is generated from the Beatty sequence (A059561) and from the complement of the Beatty sequence (A059562) for log(Pi).

Crossrefs

Programs

  • PARI
    \\ Row i of the generalized Wythoff array W(h),
    \\   where h is an irrational number between 1 and 2,
    \\   and m is the number of terms in the vectors b and c.
    row(h, i, m) = {
      if(h<=1 || h>=2, print("Invalid value for h"); return);
      my(
        b=vector(m, n, floor(n*h)),       \\ Beatty sequence for h
        c=vector(m, n, floor(n*h/(h-1))), \\ Complement of b
        w=[b[b[i]], c[b[i]]],
        j=3
      );
      while(1,
        if(j%2==1,
          if(w[j-1]<=#b, w=concat(w, b[w[j-1]]), return(w))
        ,
          if(w[j-2]<=#c, w=concat(w, c[w[j-2]]), return(w))
        );
        j++
      )
    }
    allocatemem(10^9)
    default(realprecision, 100)
    row(log(Pi), 1, 10^7)
Showing 1-5 of 5 results.