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.

A344520 Decimal expansion of 2*(1+sqrt(10))/3.

Original entry on oeis.org

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

Views

Author

Wesley Ivan Hurt, May 22 2021

Keywords

Comments

Trisect the unit square into 3 regions with equal areas from a given midpoint on the squares edge. This sequence gives the decimal expansion of the perimeter of the triangular region.

Examples

			2.7748517734455862213325956962884790...
		

Crossrefs

Similar sequences into k regions: A344554 (k=5), A343069 (k=7), A344568 (k=9), A344569 (k=17).

Programs

  • Mathematica
    RealDigits[2 (1 + Sqrt[10])/3, 10, 200][[1]] // Flatten

Formula

Decimal expansion of 2*(1 + k*sqrt(1/k^2 + 1))/k, where k = 3.