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.

A247778 Least k such that e - (1 + 1/k)^k < 1/n.

Original entry on oeis.org

1, 2, 4, 5, 6, 8, 9, 10, 12, 13, 15, 16, 17, 19, 20, 21, 23, 24, 25, 27, 28, 29, 31, 32, 34, 35, 36, 38, 39, 40, 42, 43, 44, 46, 47, 49, 50, 51, 53, 54, 55, 57, 58, 59, 61, 62, 63, 65, 66, 68, 69, 70, 72, 73, 74, 76, 77, 78, 80, 81, 82, 84, 85, 87, 88, 89
Offset: 1

Views

Author

Clark Kimberling, Sep 23 2014

Keywords

Comments

a(n+1) - a(n) is in {1,2} for n >= 1.

Examples

			The values of e - (1 + 1/k)^k for k = 1..8 are approximately 0.718282, 0.468282, 0.347911, 0.276876, 0.229962, 0.196655, 0.171782, 0.152497, so that the first 6 terms of A247778 are 1,2,4,5,6,8.
		

Crossrefs

Programs

  • Mathematica
    z = 600; f[n_] := f[n] = Select[Range[z], E - (1 + 1/#)^# < 1/n &, 1];
    u = Flatten[Table[f[n], {n, 1, z}]]       (*A247778*)
    d1 = Flatten[Position[Differences[u], 1]] (*A247779*)
    d2 = Flatten[Position[Differences[u], 2]] (*A247780*)
  • PARI
    a(n) = {k = 1; while ((exp(1) - (1 + 1/k)^k) >= 1/n, k++); k;} \\ Michel Marcus, Sep 25 2014

A247785 Numbers k such that A247784(k+1) = A247784(k).

Original entry on oeis.org

2, 6, 10, 13, 17, 21, 25, 29, 32, 36, 40, 44, 47, 51, 55, 59, 63, 66, 70, 74, 78, 82, 85, 89, 93, 97, 100, 104, 108, 112, 116, 119, 123, 127, 131, 135, 138, 142, 146, 150, 153, 157, 161, 165, 169, 172, 176, 180, 184, 187, 191, 195, 199, 203, 206, 210, 214
Offset: 1

Views

Author

Clark Kimberling, Sep 24 2014

Keywords

Comments

A247785 and A247786 are a complementary pair.

Crossrefs

Programs

  • Mathematica
    z = 200; t = Table[Floor[1/(E - (1 + 1/k)^k)], {k, 1, z}]  (*A247784*)
    d = Differences[t]
    Flatten[Position[d, 0]]  (*A247785*)
    Flatten[Position[d, 1]]  (*A247786*)

A247780 Numbers k such that A247778(k+1) - A247778(k) = 2.

Original entry on oeis.org

2, 5, 8, 10, 13, 16, 19, 22, 24, 27, 30, 33, 35, 38, 41, 44, 47, 49, 52, 55, 58, 61, 63, 66, 69, 72, 74, 77, 80, 83, 86, 88, 91, 94, 97, 100, 102, 105, 108, 111, 113, 116, 119, 122, 125, 127, 130, 133, 136, 138, 141, 144, 147, 150, 152, 155, 158, 161, 164
Offset: 1

Views

Author

Clark Kimberling, Sep 23 2014

Keywords

Comments

Complement of A247779.

Examples

			The values of e - (1 + 1/k)^k for k = 1..8 are approximately 0.718282, 0.468282, 0.347911, 0.276876, 0.229962, 0.196655, 0.171782, 0.152497, so that the first 6 terms of A247778 are 1,2,4,5,6,8, and the first three terms of A247780 are 1,3,4.
		

Crossrefs

Programs

  • Mathematica
    z = 600; f[n_] := f[n] = Select[Range[z], E - (1 + 1/#)^# < 1/n &, 1];
    u = Flatten[Table[f[n], {n, 1, z}]]       (*A247778*)
    d1 = Flatten[Position[Differences[u], 1]] (*A247779*)
    d2 = Flatten[Position[Differences[u], 2]] (*A247780*)
Showing 1-3 of 3 results.