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.

User: Brian J. Harrild

Brian J. Harrild's wiki page.

Brian J. Harrild has authored 1 sequences.

A319617 Number of Integer solutions to w^2 + x^2 + y^2 + z^2 < n^2; number of lattice points inside a 4-sphere of radius n.

Original entry on oeis.org

0, 1, 65, 321, 1257, 2873, 6265, 11377, 20161, 31665, 48945, 71401, 102041, 139481, 188753, 247329, 323697, 409457, 516121, 640393, 789161, 955793, 1153025, 1376305, 1637929, 1921049, 2252889, 2615673, 3033665, 3483633, 3990753, 4547945, 5173145, 5840393, 6589945, 7395921, 8287297, 9238001, 10281977, 11402457, 12633145, 13929377
Offset: 0

Author

Brian J. Harrild, Sep 24 2018

Keywords

Examples

			For n=2 there are 65 lattice points in Z^4 such that w^2+x^2+y^2+x^2 < 4
		

Crossrefs

a(n) = A055410(n) - A267326(n).

Programs

  • Python
    for n in range (0,51):
        NumPoints=0
        for w in range (-n,n+1):
            for x in range (-n,n+1):
                for y in range (-n,n+1):
                    for z in range (-n,n+1):
                        if w**2+x**2+y**2+z**2