A192684 Floor-Sqrt transform of numbers of A004148 (secondary structures).

1, 1, 1, 1, 2, 2, 4, 6, 9, 13, 20, 31, 47, 73, 112, 174, 269, 418, 651, 1015, 1586, 2481, 3886, 6095, 9571, 15048, 23684, 37312, 58837, 92857, 146667, 231831, 366707, 580438, 919314, 1456898, 2310137, 3665024, 5817475, 9238469, 14677875, 23329993, 37097578, 59013025, 93910464, 149498476

Offset

0,5

Links

Table of n, a(n) for n=0..45.

Formula

a(n) = floor(sqrt(A004148(n))).

Mathematica

 FSFromSeries[f_, x_, n_] := Map[Floor[Sqrt[#]]&, CoefficientList[Series[f, {x, 0, n}], x]]
FSFromSeries[(1-x+x^2-Sqrt[1-2x-x^2-2x^3+x^4])/(2x^2), x, 100]

Crossrefs

Sequence in context: A362260 A306730 A209603 * A274147 A226496 A047084

Adjacent sequences: A192681 A192682 A192683 * A192685 A192686 A192687

Keyword

nonn

Author

Emanuele Munarini, Jul 07 2011

Status

approved