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.

A083055 a(n) = cardinality{ k<=n / A083054(k)=1}.

Original entry on oeis.org

1, 1, 1, 1, 1, 2, 2, 3, 3, 3, 4, 4, 5, 5, 6, 6, 6, 7, 7, 8, 8, 8, 8, 8, 9, 9, 10, 10, 10, 10, 10, 11, 11, 12, 12, 12, 13, 13, 14, 14, 14, 14, 14, 15, 15, 16, 16, 16, 16, 16, 17, 17, 18, 18, 18, 18, 18, 19, 19, 20, 20, 20, 21, 21, 22, 22, 22, 22, 22, 23, 23, 24, 24, 24, 24, 24, 25, 25
Offset: 1

Views

Author

Benoit Cloitre, Apr 18 2003

Keywords

Crossrefs

Programs

  • PARI
    {a(n)=if(n<1,0, sum(k=1,n,sqrtint(3*k^2)-3*sqrtint(k^2\3)==1))} /* Michael Somos, Aug 31 2006 */

Formula

a(n) = n/3 + O(n) (it seems O(n) could be replaced with O(log(n))).

A083057 A fractal sequence.

Original entry on oeis.org

2, 3, 3, 2, 0, 0, -1, 0, 0, -1, 0, 0, 2, 3, 6, 8, 9, 12, 14, 18, 21, 23, 24, 24, 26, 27, 30, 32, 33, 33, 32, 33, 33, 35, 36, 36, 38, 39, 42, 44, 45, 45, 44, 45, 45, 47, 48, 48, 47, 45, 45, 44, 45, 45, 44, 42, 39, 38, 36, 36, 35, 33, 33, 32, 33, 33, 32, 30, 27, 26, 24, 24, 23, 21, 18, 14, 12, 9, 8, 6, 3, 2, 0, 0, -1, 0, 0, -1, 0, 0, 2, 3, 3, 2, 0
Offset: 1

Views

Author

Benoit Cloitre, Apr 18 2003

Keywords

Crossrefs

Formula

a(n)=sum(k=1, n, A083056(k))

A083056 a(n) = 3*A083055(n)-n.

Original entry on oeis.org

2, 1, 0, -1, -2, 0, -1, 1, 0, -1, 1, 0, 2, 1, 3, 2, 1, 3, 2, 4, 3, 2, 1, 0, 2, 1, 3, 2, 1, 0, -1, 1, 0, 2, 1, 0, 2, 1, 3, 2, 1, 0, -1, 1, 0, 2, 1, 0, -1, -2, 0, -1, 1, 0, -1, -2, -3, -1, -2, 0, -1, -2, 0, -1, 1, 0, -1, -2, -3, -1, -2, 0, -1, -2, -3, -4, -2, -3, -1, -2, -3, -1, -2, 0, -1, 1, 0, -1, 1, 0, 2, 1, 0, -1, -2, 0, -1, 1, 0, -1, -2, -3, -1, -2, 0
Offset: 1

Views

Author

Benoit Cloitre, Apr 18 2003

Keywords

Crossrefs

Showing 1-3 of 3 results.