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.

A317331 Indices m for which A058304(m) = 1.

Original entry on oeis.org

4, 8, 11, 16, 20, 23, 27, 32, 36, 40, 43, 47, 52, 55, 59, 64, 68, 72, 75, 80, 84, 87, 91, 95, 100, 104, 107, 111, 116, 119, 123, 128, 132, 136, 139, 144, 148, 151, 155, 160, 164, 168, 171, 175, 180, 183, 187, 191, 196, 200, 203, 208, 212, 215, 219, 223, 228, 232, 235, 239, 244, 247, 251
Offset: 1

Views

Author

A.H.M. Smeets, Jul 26 2018

Keywords

Crossrefs

Programs

  • Python
    n, f, i, p, q = 1, 1, 0, 0, 1
    while i < 100000:
        i, p, q = i+1, p*10, q*10
        if i == f:
            p, n = p+1, n+1
            f = f*n
    n, a, j = 0, 0, 0
    while p%q > 0:
        a, f, p, q = a+1, p//q, q, p%q
        if f == 1:
            n = n+1
            print(n, a-1)

Formula

a(n) = 4*n + A014577(n-1)-1. - A.H.M. Smeets, Jul 29 2018

A317332 Indices m for which A058304(m) = 8.

Original entry on oeis.org

9, 17, 22, 33, 41, 46, 54, 65, 73, 81, 86, 94, 105, 110, 118, 129, 137, 145, 150, 161, 169, 174, 182, 190, 201, 209, 214, 222, 233, 238, 246, 257, 265, 273, 278, 289, 297, 302, 310, 321, 329, 337, 342, 350, 361, 366, 374, 382, 393, 401, 406, 417, 425, 430, 438, 446, 457, 465, 470, 478, 489, 494, 502
Offset: 1

Views

Author

A.H.M. Smeets, Jul 26 2018

Keywords

Crossrefs

Programs

  • Python
    n, f, i, p, q = 1, 1, 0, 0, 1
    while i < 1000000:
        i, p, q = i+1, p*10, q*10
        if i == f:
            p, n = p+1, n+1
            f = f*n
    n, a, j = 0, 0, 0
    while p%q > 0:
        a, f, p, q = a+1, p//q, q, p%q
        if f == 8:
            n = n+1
            print(n, a-1)

Formula

a(n) = 8*n + A317335(n).

A317333 Indices m for which A058304(m) = 9.

Original entry on oeis.org

1, 6, 14, 25, 30, 38, 49, 57, 62, 70, 78, 89, 97, 102, 113, 121, 126, 134, 142, 153, 158, 166, 177, 185, 193, 198, 206, 217, 225, 230, 241, 249, 254, 262, 270, 281, 286, 294, 305, 313, 318, 326, 334, 345, 353, 358, 369, 377, 385, 390, 398, 409, 414, 422, 433, 441, 449, 454, 462, 473, 481, 486, 497, 505
Offset: 1

Views

Author

A.H.M. Smeets, Jul 26 2018

Keywords

Crossrefs

Programs

  • Python
    n, f, i, p, q = 1, 1, 0, 0, 1
    while i < 1000000:
        i, p, q = i+1, p*10, q*10
        if i == f:
            p, n = p+1, n+1
            f = f*n
    n, a, j = 0, 0, 0
    while p%q > 0:
        a, f, p, q = a+1, p//q, q, p%q
        if f == 9:
            n = n+1
            print(n, a-1)

Formula

a(n) = 8*n + A317336(n).

A012245 Characteristic function of factorial numbers; also decimal expansion of Liouville's number or Liouville's constant.

Original entry on oeis.org

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

Views

Author

Keywords

Comments

Read as decimal fraction 1100010... in any base > 1 (arbitrary decimal point) Liouville's numbers are transcendental; read as a continued fraction it is also transcendental [G. H. Hardy and E. M. Wright, Th. 192].

Examples

			a(25) = a(26) = ... = a(119) = 0 because 4! = 24 and 5! = 120.
0.110001000000000000000001000000000000000000000000000000000000000000000....
		

References

  • Calvin C. Clawson, Mathematical Mysteries, The Beauty and Magic of Numbers, Perseus Books, 1996, p. 89.
  • John H. Conway and Richard K. Guy, The Book of Numbers, pp. 239-241 (1996).
  • G. H. Hardy and E. M. Wright, An Introduction to the Theory of Numbers. 3rd ed., Oxford Univ. Press, 1954, p. 162.
  • T. W. Koerner, Fourier Analysis, Camb. Univ. Press 1988, p. 177.
  • Clifford A. Pickover, A Passion for Mathematics, Wiley, 2005; see p. 58.
  • David Wells, The Penguin Dictionary of Curious and Interesting Numbers. Penguin Books, NY, 1986, Revised edition 1987, p. 26.

Crossrefs

Cf. A000142, A058304 (continued fraction).

Programs

  • Mathematica
    With[{nn=5},ReplacePart[Table[0,{nn!}],Table[{n!},{n,nn}]->1]] (* Harvey P. Dale, Jul 22 2012 *)
    RealDigits[ Sum[1/10^n!, {n, 5}], 10, 105][[1]] (* Robert G. Wilson v, Aug 03 2018 *)
    CoefficientList[1/x Sum[x^k!, {k, 1, 5}], x] (* Jean-François Alcover, Nov 02 2018 *)
  • PARI
    default(realprecision, 20080); x=10*suminf(n=1, 1.0/10^n!) + 1/10^20040; for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b012245.txt", n, " ", d)); \\ Harry J. Smith, May 15 2009
    
  • Python
    from itertools import count
    def A012245(n):
        c = 1
        for i in count(1):
            if (c:=c*i) >= n:
                return int(c==n) # Chai Wah Wu, Jan 11 2023

Formula

G.f.: Sum_{i>=1} x^Product_{j=1..i} j. - Jon Perry, Mar 31 2004
a(A000142(n)) = 1; a(A063992(n)) = 0. - Reinhard Zumkeller, Oct 11 2008

A317413 Continued fraction for binary expansion of Liouville's number interpreted in base 2 (A092874).

Original entry on oeis.org

0, 1, 3, 3, 1, 2, 1, 4095, 3, 1, 3, 3, 1, 4722366482869645213695, 4, 3, 1, 3, 4095, 1, 2, 1, 3, 3, 1
Offset: 0

Views

Author

A.H.M. Smeets, Jul 27 2018

Keywords

Comments

The continued fraction of the number obtained by reading A012245 as binary fraction.
Except for the first term, the only values that occur in this sequence are 1, 2, 3, 4 and values 2^((m-1)*m!) - 1 for m > 2. The probability of occurrence P(a(n) = k) are given by:
P(a(n) = 1) = 1/3,
P(a(n) = 2) = 1/12,
P(a(n) = 3) = 1/3,
P(a(n) = 4) = 1/12 and
P(a(n) = 2^((m-1)*m!)-1) = 1/(3*2^(m-1)) for m > 2.
The next term is roughly 3.12174855*10^144 (see b-file for precise value).

Examples

			0.76562505... = 0+1/(1+1/(3+1/(3+1/(1+1/(2+...))))). - _R. J. Mathar_, Jun 19 2021
		

Crossrefs

Cf. A058304 (in base 10), A317414 (in base 3).

Programs

  • Maple
    with(numtheory): cfrac(add(1/2^factorial(n),n=1..7),24,'quotients'); # Muniru A Asiru, Aug 11 2018
  • Mathematica
    ContinuedFraction[ FromDigits[ RealDigits[ Sum[1/10^n!, {n, 8}], 10, 10000], 2], 60] (* Robert G. Wilson v, Aug 09 2018 *)
  • Python
    n,f,i,p,q,base = 1,1,0,0,1,2
    while i < 100000:
        i,p,q = i+1,p*base,q*base
        if i == f:
            p,n = p+1,n+1
            f = f*n
    n,a,j = 0,0,0
    while p%q > 0:
        a,f,p,q = a+1,p//q,q,p%q
        print(a-1,f)

Formula

a(n) = 1 if and only if n in A317538.
a(n) = 2 if and only if n in {24*m - 19 | m > 0} union {24*m - 4 | m > 0}.
a(n) = 3 if and only if n in A317539.
a(n) = 4 if and only if n in {12*m + A014710(m-1) - 2*(A014710(m-1) mod 2) | m > 0}
a(n) = 2^((m-1)*m!)-1 if and only if n in {3*2^(m-2)*(1+k*4) + 1 | k >= 0} union {3*2^(m-2)*(3+k*4) | k >= 0} for m > 2.

A317414 Continued fraction for ternary expansion of Liouville's number interpreted in base 3 (A012245).

Original entry on oeis.org

0, 2, 4, 8, 1, 3, 2, 531440, 1, 1, 3, 1, 8, 4, 2, 22528399544939174411840147874772640, 1, 1, 4, 8, 1, 3, 1, 1, 531440, 2, 3, 1, 8, 4, 2
Offset: 0

Views

Author

A.H.M. Smeets, Jul 27 2018

Keywords

Comments

The continued fraction of the number obtained by reading A012245 as a ternary fraction.
Except for the first term, the only values that occur in this sequence are 1,2,3,4, and values 3^((m-1)*m!)-1 for m > 1. The probability of occurrence P(a(n) = k) are given by:
P(a(n) = 1) = 3/8,
P(a(n) = 2) = 1/8,
P(a(n) = 3) = 1/8,
P(a(n) = 4) = 1/8 and
P(a(n) = 3^((m-1)*m!)-1) = 2^-(m+1) for m > 1.
More generally it seems that for any base > 2, P(a(n) <= base+1) = 3/4, P(a(n) > base+1) = 1/4, and P(a(n) = base^((m-1)*m!)-1) = 2^-(m+1) for m > 1.

Crossrefs

Cf. A058304 (in base 10), A317413 (in base 2), A317661 (in base 4).

Programs

  • Maple
    with(numtheory): cfrac(add(1/3^factorial(n),n=1..7),30,'quotients'); # Muniru A Asiru, Aug 11 2018
  • Mathematica
    ContinuedFraction[ FromDigits[ RealDigits[ Sum[1/10^n!, {n, 8}], 10, 10000], 3], 60] (* Robert G. Wilson v, Aug 09 2018 *)
  • Python
    n,f,i,p,q,base = 1,1,0,0,1,3
    while i < 100000:
        i,p,q = i+1,p*base,q*base
        if i == f:
            p,n = p+1,n+1
            f = f*n
    n,a,j = 0,0,0
    while p%q > 0:
        a,f,p,q = a+1,p//q,q,p%q
        print(a-1,f)

Formula

a(n) = 1 if and only if n in {floor(8*n/3) + A317627(n) | n > 0}.
a(n) = 2 if and only if n in {8*n - 10 + 3*A089013(n-1) | n > 0}.
a(n) = 3 if and only if n in {16*n - 11 | n > 0} union {16*n - 6 | n > 0}.
a(n) = 4 if and only if n in {16*n - 14 | n > 0} union {16*n - 3 | n > 0}.
a(n) = 3^((m-1)*m!)-1 iff n in {2^m*(1+k*4) - 1 | k >= 0} union {2^m*(3+k*4) | k >= 0} for m > 1.

A317661 Continued fraction for quaternary expansion of Liouville's number interpreted in base 4 (A012245).

Original entry on oeis.org

0, 3, 5, 15, 1, 4, 3, 16777215, 1, 2, 4, 1, 15, 5, 3, 22300745198530623141535718272648361505980415, 1, 2, 5, 15, 1, 4, 2, 1, 16777215, 3, 4, 1, 15, 5, 3
Offset: 0

Views

Author

A.H.M. Smeets, Aug 03 2018

Keywords

Crossrefs

Cf. A058304 (in base 10), A317413 (in base 2), A317414 (in base 3).

Programs

  • Maple
    with(numtheory): cfrac(add(1/4^factorial(n),n=1..7),30,'quotients'); # Muniru A Asiru, Aug 12 2018
  • Python
    n, f, i, p, q, base = 1, 1, 0, 0, 1, 4
    while i < 100000:
        i, p, q = i+1, p*base, q*base
        if i == f:
            p, n = p+1, n+1
            f = f*n
    n, a, j = 0, 0, 0
    while p%q > 0:
        a, f, p, q = a+1, p//q, q, p%q
        print(a-1, f)

Formula

In general for any Liouville's number base > 2:
a(n) = 1 if (and only if, for base > 3) n in A317331,
a(n) = base-2 if (and only if, for base > 3) n in A317332,
a(n) = base-1 if and only if n in A317333,
a(n) = base if and only if n in {8*m - 6 + 3*(m mod 2) | m > 0},
a(n) = base+1 if and only if n in {8*m - 3 - 3*(m mod 2) | m > 0},
a(n) = base^((m-1)*m!)-1 iff n in {2^m*(1+k*4) - 1 | k >= 0} union {2^m*(3+k*4) | k >= 0} for m > 1.

A359457 Continued fraction for constant A359456.

Original entry on oeis.org

0, 9, 11, 99, 1, 10, 9, 999999999999999999, 1, 8, 10, 1, 99, 11, 9
Offset: 0

Views

Author

A.H.M. Smeets, Jan 02 2023

Keywords

Comments

It seems that all terms smaller than 100 are identical to the continued fraction terms of Liouville's constant as in A058304.
Except for the first term, the only values that occur in this sequence are 1,8,9,10,11,and values 10^A359458(m-1)-1 for m > 1. The probability of occurrence P(a(n) = k) are given by:
P(a(n) = 1) = 1/4,
P(a(n) = 8) = 1/8,
P(a(n) = 9) = 1/8,
P(a(n) = 10) = 1/8,
P(a(n) = 11) = 1/8 and
P(a(n) = 10^A359458(m-1)-1) = 2^-(m+1) for m > 1.

Crossrefs

Formula

a(n) = 1 if and only if n in A317331,
a(n) = 8 if and only if n in A317332,
a(n) = 9 if and only if n in A317333,
a(n) = 10 if and only if n = 8*m - 6 + 3*(m mod 2) for m > 0,
a(n) = 11 if and only if n = 8*m - 3 - 3*(m mod 2) for m > 0,
a(n) = 10^A359458(m-1)-1 if and only if n in {2^m*(1+k*4) - 1 | k >= 0} union {2^m*(3+k*4) | k >= 0} for m > 1.
Showing 1-8 of 8 results.