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

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

1,1

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.

Links

Table of n, a(n) for n=1..94.

Formula

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

Example

2.7748517734455862213325956962884790...

Mathematica

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

Crossrefs

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

Sequence in context: A244645 A277527 A188636 * A021977 A057105 A016536

Adjacent sequences: A344517 A344518 A344519 * A344521 A344522 A344523

Keyword

nonn,cons

Author

Wesley Ivan Hurt, May 22 2021

Status

approved