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

1,1

Comments

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

Links

Table of n, a(n) for n=1..30.

Eric Weisstein's World of Mathematics, Hypersphere

Eric Weisstein's World of Mathematics, Floor Function

Wikipedia, N-sphere

Formula

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

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

Mathematica

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

Prog

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

Crossrefs

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

Sequence in context: A302352 A301398 A141923 * A302124 A217215 A159682

Adjacent sequences: A261788 A261789 A261790 * A261792 A261793 A261794

Keyword

nonn

Author

Ilya Gutkovskiy, Sep 01 2015

Status

approved