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.

Previous Showing 11-20 of 20 results.

A154540 Decimal expansion of log_2 (15).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Oct 30 2009

Keywords

Examples

			3.9068905956085185293240583734372066846246458007170616725105...
		

Crossrefs

Cf. decimal expansion of log_2(m): A020857 (m=3), A020858 (m=5), A020859 (m=6), A020860 (m=7), A020861 (m=9), A020862 (m=10), A020863 (m=11), A020864 (m=12), A152590 (m=13), A154462 (m=14), this sequence, A154847 (m=17), A154905 (m=18), A154995 (m=19), A155172 (m=20), A155536 (m=21), A155693 (m=22), A155793 (m=23), A155921 (m=24).

Programs

  • Mathematica
    RealDigits[Log[2, 15], 10, 100][[1]] (* Vincenzo Librandi, Aug 29 2013 *)

A154905 Decimal expansion of log_2 (18).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Oct 30 2009

Keywords

Examples

			4.1699250014423123629074778878956330175196288153849621209115...
		

Crossrefs

Cf. decimal expansion of log_2(m): A020857 (m=3), A020858 (m=5), A020859 (m=6), A020860 (m=7), A020861 (m=9), A020862 (m=10), A020863 (m=11), A020864 (m=12), A152590 (m=13), A154462 (m=14), A154540 (m=15), A154847 (m=17), this sequence, A154995 (m=19), A155172 (m=20), A155536 (m=21), A155693 (m=22), A155793 (m=23), A155921 (m=24).

Programs

  • Mathematica
    RealDigits[Log[2,18],10,120][[1]] (* Harvey P. Dale, Jul 12 2012 *)

Formula

Equals 1 + A020861 = 1 + 2*A020857. - Jianing Song, Nov 16 2024

A154995 Decimal expansion of log_2 (19).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Oct 30 2009

Keywords

Examples

			4.2479275134435854937935194229068344226935075696615340145815...
		

Crossrefs

Cf. decimal expansion of log_2(m): A020857 (m=3), A020858 (m=5), A020859 (m=6), A020860 (m=7), A020861 (m=9), A020862 (m=10), A020863 (m=11), A020864 (m=12), A152590 (m=13), A154462 (m=14), A154540 (m=15), A154847 (m=17), A154905 (m=18), this sequence, A155172 (m=20), A155536 (m=21), A155693 (m=22), A155793 (m=23), A155921 (m=24).

Programs

  • Mathematica
    RealDigits[Log[2, 19], 10, 100][[1]] (* Vincenzo Librandi, Aug 29 2013 *)

A155536 Decimal expansion of log_2 (21).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Oct 30 2009

Keywords

Examples

			4.3923174227787602888957082611796473174008410336586218441330...
		

Crossrefs

Cf. decimal expansion of log_2(m): A020857 (m=3), A020858 (m=5), A020859 (m=6), A020860 (m=7), A020861 (m=9), A020862 (m=10), A020863 (m=11), A020864 (m=12), A152590 (m=13), A154462 (m=14), A154540 (m=15), A154847 (m=17), A154905 (m=18), A154995 (m=19), A155172 (m=20), this sequence, A155693 (m=22), A155793 (m=23), A155921 (m=24).

Programs

  • Mathematica
    RealDigits[Log[2, 21], 10, 100][[1]] (* Vincenzo Librandi, Aug 29 2013 *)

A155693 Decimal expansion of log_2 (22).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Oct 30 2009

Keywords

Examples

			4.4594316186372972561993630467257929587032315256817680713128...
		

Crossrefs

Cf. decimal expansion of log_2(m): A020857 (m=3), A020858 (m=5), A020859 (m=6), A020860 (m=7), A020861 (m=9), A020862 (m=10), A020863 (m=11), A020864 (m=12), A152590 (m=13), A154462 (m=14), A154540 (m=15), A154847 (m=17), A154905 (m=18), A154995 (m=19), A155172 (m=20), A155536 (m=21), this sequence, A155793 (m=23), A155921 (m=24).

Programs

  • Mathematica
    RealDigits[Log[2, 22], 10, 100][[1]] (* Vincenzo Librandi, Aug 29 2013 *)

Formula

Equals 1 + A020863. - Jianing Song, Nov 16 2024

A155793 Decimal expansion of log_2 (23).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Oct 30 2009

Keywords

Examples

			4.5235619560570128722941482441626688444988251254425550594944...
		

Crossrefs

Cf. decimal expansion of log_2(m): A020857 (m=3), A020858 (m=5), A020859 (m=6), A020860 (m=7), A020861 (m=9), A020862 (m=10), A020863 (m=11), A020864 (m=12), A152590 (m=13), A154462 (m=14), A154540 (m=15), A154847 (m=17), A154905 (m=18), A154995 (m=19), A155172 (m=20), A155536 (m=21), A155693 (m=22), this sequence, A155921 (m=24).

Programs

  • Mathematica
    RealDigits[Log[2, 23], 10, 100][[1]] (* Vincenzo Librandi, Aug 29 2013 *)

A229168 Define a sequence of real numbers by b(1)=2, b(n+1) = b(n) + log_2(b(n)); a(n) = smallest i such that b(i) >= 2^n.

Original entry on oeis.org

1, 3, 5, 7, 11, 17, 27, 44, 74, 127, 225, 402, 728, 1333, 2459, 4566, 8525, 15993, 30122, 56936, 107953, 205253, 391223, 747369, 1430648, 2743721, 5270959, 10141978, 19542806, 37708232, 72849931, 140905791, 272836175, 528832794, 1026008203, 1992390617
Offset: 1

Views

Author

N. J. A. Sloane, Sep 27 2013

Keywords

Examples

			The initial terms of the b(n) sequence are approximately
2, 3.00000000000000000000000, 4.58496250072115618145375, 6.78187243514238888864578, 9.54355608312733448665509, 12.7980830210090262451102, 16.4759388461842196480290, 20.5182276175427023220954, 24.8770618274970204646817, 29.5138060245244394221195, 34.3971240984210783617324, ...
b(5) is the first term >= 8, so a(3) = 5.
		

Crossrefs

Programs

  • Maple
    # A229168, A229169, A229170.
    Digits:=24;
    log2:=evalf(log(2));
    lis:=[2]; a:=2;
    t1:=[1]; l:=2;
    for i from 2 to 128 do
    a:=evalf(a+log(a)/log2);
    if a >= 2^l then
    l:=l+1; t1:=[op(t1),i]; fi;
    lis:=[op(lis),a];
    od:
    lis;
    map(floor,lis);
    map(ceil,lis);
    t1;
  • PARI
    n=1; p2=2^n; m=2; lg2=log(2); for(i=1, 1992390617, if(m>=p2, print(n " " i); n++; p2=2^n); m=m+log(m)/lg2) /* Donovan Johnson, Oct 04 2013 */

Extensions

a(11)-a(36) from Donovan Johnson, Oct 04 2013

A229170 Define a sequence of real numbers by b(1)=2, b(n+1) = b(n) + log_2(b(n)); a(n) = ceiling( b(n) ).

Original entry on oeis.org

2, 3, 5, 7, 10, 13, 17, 21, 25, 30, 35, 40, 45, 51, 56, 62, 68, 74, 80, 87, 93, 100, 106, 113, 120, 127, 134, 141, 148, 155, 162, 170, 177, 185, 192, 200, 207, 215, 223, 231, 239, 246, 254, 262, 270, 278, 287, 295, 303, 311, 319, 328, 336, 345, 353, 361, 370, 378, 387, 396, 404, 413, 422, 430, 439, 448, 457, 465, 474
Offset: 1

Views

Author

N. J. A. Sloane, Sep 27 2013

Keywords

Examples

			Comment from _N. J. A. Sloane_, Jun 07 2023: (Start)
b(1) to b(4) are:
  [2, 3, 3+ln(3)/ln(2), 3+ln(3)/ln(2)+ln(3+ln(3)/ln(2))/ln(2)]
b(1) to b(6) computed exactly and THEN converted to floating point are:
  2., 3., 4.58496250072115618145373894394, 6.78187243514238888864576363676, 9.54355608312733448665507868324, 12.7980830210090262451101642020. (End)
		

Crossrefs

Programs

  • Mathematica
    Ceiling[NestList[N[#+Log2[#],1000]&,2,70]] (* Caution: this program uses an arbitrary cut-off at 1000 digits precision. - N. J. A. Sloane, Jun 07 2023 *) (* Harvey P. Dale, Jun 10 2023 *)

A229169 Define a sequence of real numbers by b(1)=2, b(n+1) = b(n) + log_2(b(n)); a(n) = floor( b(n) ).

Original entry on oeis.org

2, 3, 4, 6, 9, 12, 16, 20, 24, 29, 34, 39, 44, 50, 55, 61, 67, 73, 79, 86, 92, 99, 105, 112, 119, 126, 133, 140, 147, 154, 161, 169, 176, 184, 191, 199, 206, 214, 222, 230, 238, 245, 253, 261, 269, 277, 286, 294, 302, 310, 318, 327, 335, 344, 352, 360, 369, 377, 386, 395, 403, 412, 421, 429, 438, 447, 456, 464, 473, 482
Offset: 1

Views

Author

N. J. A. Sloane, Sep 27 2013

Keywords

Crossrefs

A229177 Decimal expansion of 3 + log_2(3) + log_2(3 + log_2(3)).

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Sep 28 2013

Keywords

Comments

This is the fourth term in the sequence of real numbers discussed in A229168-A229170.

Examples

			6.7818724351423888886457636367782053029041818834546993272707...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[3 + Log2[3] + Log2[3 + Log2[3]], 10, 120][[1]] (* Amiram Eldar, Jun 06 2023 *)
Previous Showing 11-20 of 20 results.