A228391 Volume of elliptic cone (rounded down) with semi-minor axis = height = n and semi-major axis = 3*n/2.

1, 12, 42, 100, 196, 339, 538, 804, 1145, 1570, 2090, 2714, 3451, 4310, 5301, 6433, 7717, 9160, 10774, 12566, 14547, 16725, 19111, 21714, 24543, 27608, 30917, 34482, 38310, 42411, 46795, 51471, 56449, 61738, 67347, 73287, 79565, 86192, 93178, 100530, 108260, 116377

Offset

1,2

Links

K. D. Bajpai, Table of n, a(n) for n = 1..5000

Formula

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

Example

a(9) = 1145 since volume = ((Pi*n*1.5*n)*(n)/3) = ((Pi*9*1.5*9)*(9)/3) = 1145.110522 and floor(1145.110522) = 1145.

Maple

KD := proc() local a; a:= floor(((Pi*n*1.5*n)*(n)/3));
RETURN (a):
end:
seq(KD(), n=1..100);

Crossrefs

Cf. A228189 (similar sequence for right circular cone).

Sequence in context: A009948 A193068 A007586 * A334277 A122973 A074356

Adjacent sequences: A228388 A228389 A228390 * A228392 A228393 A228394

Keyword

nonn

Author

K. D. Bajpai, Aug 21 2013

Status

approved