One of the hydrogen spectral series.

One of the hydrogen spectral series, lying in the far infrared band.

(baseball) The best-of-seven series of games to determine the winner of each of the National League and the American League.

A standardized art therapy assessment in which the artist/patient is asked to draw three pictures. / An international collaborative project on how people tend to draw.

(physics) Any of several series of spectral lines of hydrogen that correspond to quantum transitions between the various allowed energy levels of the hydrogen atom.

a Fourier series consisting solely of sine functions

a Fourier series consisting solely of cosine functions

(Singapore) A compilation of national examination questions from past years.

(mathematics, algebra) Any finite or infinite series of the form a_0+a_1x+a_2x²…=∑ᵢa_ixⁱ, where the aᵢ are numbers, but it is understood that no value is assigned to x.

The second division of professional football in Italy.