OEISsequences 0.0.2

Python functions to generate OEIS sequences

# oeis-sequences [](https://github.com/psf/black)

Python functions to generate [The On-Line Encyclopedia of Integer Sequences](https://oeis.org/) (OEIS) sequences

## Requirements Requires python >= 3.8

## Installation pip install oeis-sequences

## Usage After installation, import OEISsequences will import all the functions accessible via OEISsequences.Axxxxxx. Alternatively, invidividual functions can be imported as from OEISsequences import Axxxxxx.

For each sequence, there are 3 different kinds of functions:

1. Functions named Axxxxxx: Axxxxxx(n) returns the n-th term of OEIS sequence Axxxxxx.

2. Functions named Axxxxxx_T: returns T(n,k) for OEIS sequences where the natural definition is a 2D table T.

3. Functions named Axxxxxx_gen: Axxxxxx_gen() returns a generator of OEIS sequence Axxxxxx.

The function Axxxxxx is best used to compute a single term. The generator Axxxxxx_gen is typically defined for sequences where terms are best generated sequentially and is best used when computing a sequence of consecutive terms.

For the generator, we can for example use list(islice(Axxxxxx_gen(),10)) to return the first 10 terms of sequence Axxxxxx Alternatively, setting gen = Axxxxxx_gen() and using next(gen) returns the next term of the sequence.

Given Axxxxxx_gen, one can define a function Axxxxxx as:

` def Axxxxxx(n,offset=1): return next(islice(Axxxxxx_gen(),n-offset,None)) `

where a(offset) is the first term returned by the generator, this value of offset is the same as the offset parameter in the OEIS database.

Some functions Axxxxxx_gen contain an optional keyword startvalue that returns a generator of terms that are larger than or equal to startvalue.

## Examples

Least power of 3 having exactly n consecutive 7’s in its decimal representation. ` from OEISsequences import A131546 print(A131546(5)) >> 721 ` Minimal exponents m such that the fractional part of (10/9)^m obtains a maximum (when starting with m=1). ` from itertools import islice from OEISsequences import A153695_gen print(list(islice(A153695_gen(),10))) >> [1, 2, 3, 4, 5, 6, 13, 17, 413, 555] `

Numbers n such that n³ has one or more occurrences of exactly nine different digits. ` from OEISsequences import A235811_gen print(list(islice(A235811_gen(startvalue=1475),10))) >> [1475, 1484, 1531, 1706, 1721, 1733, 1818, 1844, 1895, 1903] `