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 1-4 of 4 results.

A233779 Main diagonal of A234951.

Original entry on oeis.org

1, 3, 5, 9, 12, 16
Offset: 1

Views

Author

Omar E. Pol, Jan 13 2014

Keywords

Crossrefs

Formula

a(n) = A234951(n,n).

A234373 Row 4 of the square array A234951.

Original entry on oeis.org

1, 4, 6, 9, 11, 14, 15, 18, 20, 23
Offset: 1

Views

Author

Omar E. Pol, Jan 13 2014

Keywords

Crossrefs

Formula

a(n) = A234951(4,n).

A339392 Numerators of the probability that when a stick is broken up at n-1 points independently and uniformly chosen at random along its length there exist 3 of the n pieces that can form a triangle.

Original entry on oeis.org

0, 0, 1, 4, 23, 53, 87, 593, 5807, 415267, 8758459, 274431867, 12856077691, 905435186299, 481691519113703, 77763074616922439, 3824113551749834107, 1437016892446437662971, 165559472503434318118655, 146602912901791088694069887, 200050146291129782743679367167
Offset: 1

Views

Author

Amiram Eldar, Dec 04 2020

Keywords

Comments

For the corresponding probability that any triple of pieces can form a triangle, see A001791. The probabilities for these two cases were found by Kong et al. (2013).

Examples

			Fractions begin with 0, 0, 1/4, 4/7, 23/28, 53/56, 87/88, 593/594, 5807/5808, 415267/415272, 8758459/8758464, 274431867/274431872, ...
For n = 1 or 2 the number of pieces is less than 3, so the probability is 0.
For n = 3, the stick is being broken into 3 pieces and the probability that they can form a triangle is 1/4, the solution to the classical broken stick problem (see, e.g., Gardner, 2001).
		

Crossrefs

Cf. A000045, A001791, A084623, A234951, A243398, A339393 (denominators).

Programs

  • Mathematica
    f = Table[k/(Fibonacci[k + 2] - 1), {k, 2, 20}]; Numerator[1 - FoldList[Times, 1, f]]

Formula

a(n) = numerator(1 - Product_{k=2..n} k/(Fibonacci(k+2)-1)).
Lim_{n->oo} a(n)/A339393(n) = 1.

A339393 Denominators of the probability that when a stick is broken up at n-1 points independently and uniformly chosen at random along its length there exist 3 of the n pieces that can form a triangle.

Original entry on oeis.org

1, 1, 4, 7, 28, 56, 88, 594, 5808, 415272, 8758464, 274431872, 12856077696, 905435186304, 481691519113728, 77763074616922464, 3824113551749834112, 1437016892446437662976, 165559472503434318118656, 146602912901791088694069888, 200050146291129782743679367168
Offset: 1

Views

Author

Amiram Eldar, Dec 04 2020

Keywords

Comments

See A339392 for details.

Crossrefs

Cf. A000045, A001791, A084623, A234951, A243398, A339392 (numerators).

Programs

  • Mathematica
    f = Table[k/(Fibonacci[k + 2] - 1), {k, 2, 20}]; Denominator[1 - FoldList[Times, 1, f]]

Formula

a(n) = denominator(1 - Product_{k=2..n} k/(Fibonacci(k+2)-1)).
Showing 1-4 of 4 results.