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 1-3 of 3 results.

A368620 a(n) is the n-digit numerator of the fraction h/k with h and k coprime positive integers at which abs(h/k-e) is minimal.

Original entry on oeis.org

3, 87, 878, 2721, 49171, 566827, 9242691, 28245729, 848456353
Offset: 1

Views

Author

Stefano Spezia, Jan 01 2024

Keywords

Comments

a(3) = 878 corresponds to the numerator of A368617.

Examples

			  n              fraction    approximated value
  -   -------------------    ------------------
  1                   3/1    3
  2                 87/32    2.71875
  3               878/323    2.7182662538699...
  4             2721/1001    2.7182817182817...
  5           49171/18089    2.7182818287356...
  6         566827/208524    2.7182818284705...
  7       9242691/3400196    2.7182818284593...
  8     28245729/10391023    2.7182818284590...
  ...
		

Crossrefs

Programs

  • Mathematica
    a[1]=3; a[n_]:=Module[{minim=Infinity},For[i = 10^(n - 1), i <= 10^n - 1, i++, For[j = Floor[i/E], j <= Ceiling[i/E], j++, If[(dist = Abs[i/j - E]) < minim && GCD[i, j] == 1, minim = dist; hmin = i]]]; hmin]; Array[a,9]

A368621 a(n) is the n-digit denominator of the fraction h/k with h and k coprime positive integers at which abs(h/k-e) is minimal.

Original entry on oeis.org

1, 32, 323, 1001, 18089, 208524, 3400196, 10391023, 312129649
Offset: 1

Views

Author

Stefano Spezia, Jan 01 2024

Keywords

Comments

a(3) = 323 corresponds to the denominator of A368617.

Examples

			  n              fraction    approximated value
  -   -------------------    ------------------
  1                   3/1    3
  2                 87/32    2.71875
  3               878/323    2.7182662538699...
  4             2721/1001    2.7182817182817...
  5           49171/18089    2.7182818287356...
  6         566827/208524    2.7182818284705...
  7       9242691/3400196    2.7182818284593...
  8     28245729/10391023    2.7182818284590...
  ...
		

Crossrefs

Programs

  • Mathematica
    a[1]=1; a[n_]:=Module[{minim=Infinity},For[i = 10^(n - 1), i <= 10^n - 1, i++, For[j = Floor[i/E], j <= Ceiling[i/E], j++, If[(dist = Abs[i/j - E]) < minim && GCD[i, j] == 1, minim = dist; kmin = j]]]; kmin]; Array[a,9]

A368658 a(n) is the number of correct decimal digits of e obtained from the fraction A368618(n)/A368619(n).

Original entry on oeis.org

0, 2, 5, 3, 5, 5, 7, 7, 9, 10, 11, 11, 12, 13
Offset: 1

Views

Author

Stefano Spezia, Jan 02 2024

Keywords

Examples

			a(8) = 7 since A368618(8)/A368619(8) = 24988942/9192919 = 2.7182815382143... matches the first 7 digits of e: 2.7182818284590...
		

Crossrefs

Showing 1-3 of 3 results.