A097281 Integer part of the area of integer triangle [A001611(n), A001611(n+1), A001611(n+2)].

0, 1, 2, 5, 9, 18, 35, 71, 144, 294, 601, 1231, 2526, 5191, 10672, 21950, 45159, 92920, 191214, 393512, 809864, 1666775, 3430425, 7060297, 14531166, 29907455, 61554442, 126689294, 260747884, 536663296, 1104544280, 2273340315

Offset

0,3

Links

Table of n, a(n) for n=0..31.

Formula

a(n) = floor(sqrt(s(n) * (s(n)-A001611(n)) * (s(n)-A001611(n+1)) * (s(n)-A001611(n+2)))), where s(n) is the semiperimeter: s(n) = A097280(n)/2.

Crossrefs

Sequence in context: A351983 A247322 A348473 * A321408 A289976 A068036

Adjacent sequences: A097278 A097279 A097280 * A097282 A097283 A097284

Keyword

nonn

Author

Reinhard Zumkeller, Aug 04 2004

Status

approved