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.

A004685 Fibonacci numbers written in base 2.

Original entry on oeis.org

0, 1, 1, 10, 11, 101, 1000, 1101, 10101, 100010, 110111, 1011001, 10010000, 11101001, 101111001, 1001100010, 1111011011, 11000111101, 101000011000, 1000001010101, 1101001101101, 10101011000010, 100010100101111, 110111111110001, 1011010100100000, 10010010100010001
Offset: 0

Views

Author

N. J. A. Sloane

Keywords

Links

Crossrefs

Cf. A004686 .. A004694: Fibonacci numbers written in base 3, 4, ..., 13.
Cf. A004676 .. A004684: Primes written in base 2, 3, 4, ..., 11.
Cf. A004643, ..., A004668 : powers of 2 resp. of 3 in base 3, 4, 5, ..., 26.

Programs

  • Magma
    [Seqint(Intseq(Fibonacci(n),2)): n in [0..50]]; // G. C. Greubel, Oct 09 2018
  • Maple
    with(combinat): seq(convert(fibonacci(n),binary),n=0..25); # Muniru A Asiru, Oct 10 2018
  • Mathematica
    Table[FromDigits[IntegerDigits[Fibonacci[n], 2]], {n, 0, 30}] (* Stefan Steinerberger, Apr 14 2006 *)
  • PARI
    a(n)=subst(Pol(binary(fibonacci(n))),'x,10) \\ Charles R Greathouse IV, Feb 03 2014
  • PARI
    apply( n->fromdigits(binary(fibonacci(n))), [0..19]) \\ M. F. Hasler, Jun 22 2018
  • PARI
    vector(50, n, n--; fromdigits(digits(fibonacci(n), 2))) \\ G. C. Greubel, Oct 09 2018

Formula

a(n) = A007088(A000045(n)). - Jonathan Vos Post, Aug 24 2010

A004678 Primes written in base 4.

Original entry on oeis.org

2, 3, 11, 13, 23, 31, 101, 103, 113, 131, 133, 211, 221, 223, 233, 311, 323, 331, 1003, 1013, 1021, 1033, 1103, 1121, 1201, 1211, 1213, 1223, 1231, 1301, 1333, 2003, 2021, 2023, 2111, 2113, 2131, 2203, 2213, 2231, 2303, 2311, 2333, 3001, 3011, 3013
Offset: 1

Views

Author

N. J. A. Sloane

Keywords

Links

Crossrefs

Analogs in other bases: A004676 (base 2), A001363 (base 3), A004679 (base 5), A004680 (base 6), A004681 (base 7), A004682 (base 8), A004683 (base 9), A000040 (base 10), A004684 (base 11).
Cf. A072805 (primes of form 4k+3 written in base 3).

Programs

  • Magma
    [Seqint(Intseq(NthPrime(n), 4)): n in [1..60]]; // G. C. Greubel, Oct 12 2018
  • Mathematica
    FromDigits/@IntegerDigits[Prime[Range[50]],4] (* Vincenzo Librandi, Sep 03 2016 *)
  • PARI
    a(n)=subst(Pol(digits(prime(n),4)),'x,10) \\ Charles R Greathouse IV, Nov 06 2013

Formula

a(n) = A007090(A000040(n)). - Jonathan Vos Post, Sep 09 2006

Extensions

More terms from Vincenzo Librandi, Sep 03 2016

A001363 Primes in ternary.

Original entry on oeis.org

2, 10, 12, 21, 102, 111, 122, 201, 212, 1002, 1011, 1101, 1112, 1121, 1202, 1222, 2012, 2021, 2111, 2122, 2201, 2221, 10002, 10022, 10121, 10202, 10211, 10222, 11001, 11012, 11201, 11212, 12002, 12011, 12112, 12121, 12211, 20001, 20012, 20102, 20122, 20201
Offset: 1

Views

Author

N. J. A. Sloane

Keywords

Comments

Primes written in base 3.

References

  • Archimedeans Problems Drive, Eureka, 23 (1960), 23.
  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Crossrefs

Analogs in other bases: A004676 (base 2), A001363 (base 3), A004678 (base 4), A004679 (base 5), A004680 (base 6), A004681 (base 7), A004682 (base 8), A004683 (base 9), A000040 (base 10), A004684 (base 11).
Cf. A007089, A072805 (primes of form 4k+3 written in base 3).

Programs

  • Mathematica
    Table[FromDigits[IntegerDigits[Prime[n], 3]], {n, 50}] (* T. D. Noe, Jun 28 2012 *)
  • PARI
    a(n)=subst(Pol(digits(prime(n),3)),'x,10) \\ Charles R Greathouse IV, Nov 06 2013

Formula

a(n) = A007089(A000040(n)). - Jonathan Vos Post, Sep 09 2006

Extensions

More terms from James Sellers, May 01 2000

A004680 Primes written in base 6.

Original entry on oeis.org

2, 3, 5, 11, 15, 21, 25, 31, 35, 45, 51, 101, 105, 111, 115, 125, 135, 141, 151, 155, 201, 211, 215, 225, 241, 245, 251, 255, 301, 305, 331, 335, 345, 351, 405, 411, 421, 431, 435, 445, 455, 501, 515, 521, 525, 531, 551, 1011, 1015, 1021, 1025, 1035
Offset: 1

Views

Author

N. J. A. Sloane

Keywords

Links

Crossrefs

Analogs in other bases: A004676 (base 2), A001363 (base 3), A004678 (base 4), A004679 (base 5), A004681 (base 7), A004682 (base 8), A004683 (base 9), A000040 (base 10), A004684 (base 11).
Cf. A007092.

Programs

  • Magma
    [Seqint(Intseq(NthPrime(n),6)): n in [1..60]]; // G. C. Greubel, Oct 10 2018
  • Mathematica
    FromDigits/@IntegerDigits[Prime[Range[50]], 6] (* Vincenzo Librandi, Sep 03 2016 *)
  • PARI
    a(n)=subst(Pol(digits(prime(n),6)),'x,10) \\ Charles R Greathouse IV, Nov 06 2013
  • PARI
    vector(60, n, fromdigits(digits(prime(n), 6))) \\ G. C. Greubel, Oct 10 2018

Formula

a(n) = A007092(prime(n)). - Michel Marcus, Sep 03 2016

A004640 Cubes written in base 11. (Next term contains a non-decimal character.)

Original entry on oeis.org

1, 8, 25, 59, 104, 187, 292, 426, 603
Offset: 1

Views

Author

N. J. A. Sloane

Keywords

Links

Crossrefs

Cf. A000578, A004632-A004639 (cubes written in base 2-9).

Programs

  • PARI
    a(n) = my(d=digits(n^3, 11)); my(s="", x); for(i=1, #d, if(d[i]<10, x = d[i], x = "A"); s = concat(s, x)); s \\ Jianing Song, May 22 2024, after Michel Marcus's program for A004684
Showing 1-5 of 5 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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