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 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. 0
 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS EXAMPLE For n=2 there are 65 lattice points in Z^4 such that w^2+x^2+y^2+x^2 < 4 PROG (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

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Last modified April 21 12:22 EDT 2021. Contains 343150 sequences. (Running on oeis4.)