A192670 Floor-Sqrt transform of central trinomial coefficients (A002426).

1, 1, 1, 2, 4, 7, 11, 19, 33, 56, 94, 160, 271, 461, 785, 1337, 2279, 3890, 6644, 11357, 19426, 33246, 56930, 97535, 167177, 286665, 491745, 843842, 1448530, 2487302, 4272238, 7340067, 12614059, 21682694, 37279415, 64108676, 110268453, 189700207, 326408942, 561733093, 966869803

Offset

0,4

Links

G. C. Greubel, Table of n, a(n) for n = 0..1000

Formula

a(n) = floor(sqrt(trinomial(2*n,n))).

Mathematica

FSFromSeries[f_, x_, n_] := Map[Floor[Sqrt[#]]&, CoefficientList[Series[f, {x, 0, n}], x]]
FSFromSeries[1/Sqrt[1-2x-3x^2], x, 100]

Crossrefs

Sequence in context: A003292 A007864 A277271 * A118647 A000802 A236392

Adjacent sequences: A192667 A192668 A192669 * A192671 A192672 A192673

Keyword

nonn

Author

Emanuele Munarini, Jul 07 2011

Status

approved