A261791 The integer part of the surface area of the 4-dimensional sphere of radius n.

19, 157, 532, 1263, 2467, 4263, 6770, 10106, 14389, 19739, 26272, 34109, 43367, 54164, 66619, 80851, 96978, 115119, 135391, 157913, 182804, 210183, 240166, 272874, 308425, 346936, 388526, 433315, 481419, 532958

Offset: 1

Author

Ilya Gutkovskiy, Sep 01 2015

Keywords

• nonn

Comments

2*Pi^2*n^3 - surface area of the 4-dimensional sphere of radius n.

Links

• Eric Weisstein's World of Mathematics, Hypersphere
• Eric Weisstein's World of Mathematics, Floor Function
• Wikipedia, N-sphere

Crossrefs

Cf. A038130, A000578, A164102 (2*Pi^2), A210519, A066644.

Programs

Mathematica

Table[Floor[2 Pi^2 n^3], {n, 1, 30}]

PARI

a(n) = floor(2*Pi^2*n^3) \\ Charles R Greathouse IV, Sep 18 2015

Formula

a(n) = floor(2*Pi^2*n^3).

a(n) = floor(2*Pi^2*A000578(n)).