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 1-6 of 6 results.

A079940 Greedy fractional multiples of 1/e: a(1)=1, Sum_{n>0} frac(a(n)/e) = 1.

Original entry on oeis.org

1, 3, 4, 11, 87, 193, 386, 579, 1457, 23225, 49171, 98342, 147513, 196684, 566827, 13580623, 28245729, 56491458, 84737187, 112982916, 438351041, 466596770, 494842499
Offset: 1

Views

Author

Benoit Cloitre and Paul D. Hanna, Jan 21 2003

Keywords

Comments

The n-th greedy fractional multiple of x is the smallest integer m that does not cause Sum_{k=1..n} frac(m*x) to exceed unity; an infinite number of terms appear as the denominators of the convergents to the continued fraction of 1/e.
After a(20), there is only 109305220 - 297122396/e = ~1.06317354345346734...*10^-8 to work with.

Examples

			a(4) = 11 since frac(1x) + frac(3x) + frac(4x) + frac(11x) < 1, while frac(1x) + frac(3x) + frac(4x) + frac(k*x) > 1 for all k>4 and k<11.
		

Crossrefs

Cf. A007676 (numerators of convergents to e), A079934, A079939, A079941.

Programs

  • Maple
    Digits := 100: a := []: s := 0: x := 1.0/exp(1.0): for n from 1 to 1000000 do: temp := evalf(s+frac(n*x)): if (temp<1.0) then a := [op(a),n]: print(n): s := s+evalf(frac(n*x)): fi: od: a;
  • Mathematica
    a[1] = 1; a[n_] := a[n] = Block[{k = a[n - 1] + 1, ps = Plus @@ Table[ FractionalPart[ a[i]*E^-1], {i, n - 1}]}, While[ ps + FractionalPart[k*E^-1] > 1, k++ ]; a[n] = k]; Do[ Print[ a[n]], {n, 20}] (* Robert G. Wilson v, Nov 03 2004 *)

Extensions

More terms from Mark Hudson (mrmarkhudson(AT)hotmail.com), Jan 30 2003
a(16)-a(20) from Robert G. Wilson v, Nov 03 2004
a(21)-a(23) from Sean A. Irvine, Aug 30 2025

A080142 Greedy frac multiples of 1/Pi: a(1)=1, Sum_{n>0} frac(a(n)*x) = 1 at x=1/Pi, where "frac(y)" denotes the fractional part of y.

Original entry on oeis.org

1, 2, 22, 44, 66, 88, 110, 355, 710, 1065, 1420, 1775, 2130, 2485, 2840, 3195, 3550, 3905, 4260, 4615, 4970, 5325, 5680, 6035, 6390, 6745, 7100, 7455, 7810, 8165, 104348, 104703, 105058, 105413, 105768, 208696, 209051, 312689, 313044, 417037
Offset: 1

Views

Author

Mark Hudson (mrmarkhudson(AT)hotmail.com), Jan 30 2003

Keywords

Comments

The n-th greedy frac multiple of x is the smallest integer that does not cause Sum_{k=1..n} frac(a(k)*x) to exceed unity; an infinite number of terms appear as the denominators of the convergents to the continued fraction of x.

Examples

			a(3) = 22 since frac(1x) + frac(2x) + frac(22x) < 1, while frac(1x) + frac(2x) + frac(k*x) > 1 for all k>2 and k<22.
		

Crossrefs

Programs

  • Maple
    Digits := 1000: a := []: s := 0: x := evalf(1.0/Pi): for n from 1 to 10000000 do: temp := evalf(s+frac(n*x)): if (temp<1.0) then a := [op(a),n]: print(n): s := s+evalf(frac(n*x)): fi: od: a;
  • Mathematica
    a[1] = 1; a[n_] := a[n] = Block[{k = a[n - 1] + 1, fps = Plus @@ Table[FractionalPart[a[i]*Pi^-1], {i, n - 1}]}, While[fps + FractionalPart[k*Pi^-1] > 1, k++ ]; a[n] = k]; Do[ Print[ a[n]], {n, 40}] (* Robert G. Wilson v, Nov 03 2004 *)

A079943 Denominators of the convergents of the continued fraction for log(2).

Original entry on oeis.org

1, 3, 10, 13, 88, 277, 365, 642, 1649, 2291, 3940, 6231, 10171, 36744, 377611, 414355, 791966, 1206321, 3204608, 4410929, 7615537, 12026466, 19642003, 70952475, 161546953, 555593334, 717140287, 9878417065, 69866059742, 289342656033
Offset: 1

Views

Author

Paul D. Hanna, Jan 19 2003

Keywords

Examples

			9/13 = 0.6923076923076923...
61/88 = 0.69318181818181818...
192/277 = 0.6931407942238267148...
...
log(2) = 0.6931471805599453...
		

Crossrefs

Cf. A002162 (decimal expansion of log(2)), A079941, A079942 (numerators).

A079942 Numerators of the convergents of the continued fraction for log(2).

Original entry on oeis.org

0, 1, 2, 7, 9, 61, 192, 253, 445, 1143, 1588, 2731, 4319, 7050, 25469, 261740, 287209, 548949, 836158, 2221265, 3057423, 5278688, 8336111, 13614799, 49180508, 111975815, 385107953, 497083768, 6847196937, 48427462327, 200557046245, 248984508572, 449541554817
Offset: 1

Views

Author

Paul D. Hanna, Jan 19 2003

Keywords

Examples

			9/13 = 0.6923076923076923...
61/88 = 0.69318181818181818...
192/277 = 0.6931407942238267148...
...
log(2) = 0.6931471805599453...
		

Crossrefs

Cf. A002162 (decimal expansion of log(2)), A079941, A079943 (denominators).

Programs

  • Mathematica
    Convergents[ContinuedFraction[Log[2],40]]//Numerator (* Harvey P. Dale, Jun 05 2021 *)

Extensions

Corrected and extended by Harvey P. Dale, Jun 05 2021

A080157 Greedy frac multiples of gamma: a(1)=1, Sum_{n>0} frac(a(n)*x) = 1 at x=gamma, where "frac(y)" denotes the fractional part of y.

Original entry on oeis.org

1, 2, 7, 9, 26, 52, 149, 272, 395, 790, 1185, 1580, 5653, 10911, 16169, 26685, 58628, 85313, 117256, 175884, 559595, 2179752, 5420066
Offset: 1

Views

Author

Mark Hudson (mrmarkhudson(AT)hotmail.com), Jan 31 2003

Keywords

Examples

			a(3) = 7 since frac(1x) + frac(2x) + frac(7x) < 1, while frac(1x) + frac(2x) + frac(k*x) > 1 for all k>2 and k<7.
		

Crossrefs

Programs

  • Maple
    Digits := 1000: a := []: s := 0: x := evalf(gamma): for n from 1 to 10000000 do: temp := evalf(s+frac(n*x)): if (temp<1.0) then a := [op(a),n]: print(n): s := s+evalf(frac(n*x)): fi: od: a;

A080158 Greedy frac multiples of Catalan's constant, G: a(1)=1, Sum_{n>0} frac(a(n)*x) = 1 at x=G=A006752, where "frac(y)" denotes the fractional part of y.

Original entry on oeis.org

1, 11, 107, 10579, 21158, 53014, 106028, 625708, 721157, 1442314, 2163471, 2884628, 3605785, 4326942, 16682060, 66007083, 115332106, 164657129, 329314258, 493971387, 658628516
Offset: 1

Views

Author

Mark Hudson (mrmarkhudson(AT)hotmail.com), Jan 31 2003

Keywords

Comments

For definition of how the "Greedy Frac" sequence is defined, see A079938.

Examples

			a(3) = 107 since frac(1x) + frac(11x) + frac(107x) < 1, while frac(1x) + frac(11x) + frac(k*x) > 1 for all k>11 and k<107.
		

Crossrefs

Programs

  • Maple
    Digits := 1000: a := []: s := 0: x := evalf(Catalan): for n from 1 to 5000000 do: temp := evalf(s+frac(n*x)): if (temp<1.0) then a := [op(a),n]: print(n): s := s+evalf(frac(n*x)): fi: od: a;

Extensions

a(15)-a(21) from Sean A. Irvine, Sep 05 2025
Showing 1-6 of 6 results.