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calendar
2018

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A070211 (thumbnail)
A118890 (thumbnail) A213497 (thumbnail) A124255 (thumbnail) A056283 (thumbnail)
A267255 (thumbnail) A149037 (thumbnail) A121551 (thumbnail) A271996 (thumbnail)
A229915 (thumbnail) A240059 (thumbnail) A133736 (thumbnail) A005905 (thumbnail)

Cover

A070211

A070211

a(n) is the number of compositions (ordered partitions) of n that are concave sequences.

a(8) = 24 is illustrated; a(35) = 2018


January

A118890

A118890

T(n,k) is the number of binary sequences of length n containing k subsequences 0110.

a(25) = T(11,2) = 142 is illustrated; a(38) = T(14,2) = 2018


Febuary

A213497

A213497

a(n) is the number of (w,x,y) with all terms in {0,...,n} and w = min(|w-x|,|x-y|).

a(5) = 40 is illustrated; a(40) = 2018


March

A124255

A124255

a(n) is the square of the distance to most distant visible tree of radius 1/n.

a(8) = 61 is illustrated; a(45) = 2018


April

A056283

A056283

a(n) is the number of n-bead necklaces with exactly three different colored beads.

a(5) = 30 is illustrated; a(8) = 2018


May

A267255

A267255

a(n) is the decimal representation of the n-th iteration of the "Rule 111" elementary cellular automaton.

a(5) = 2018 is illustrated


June

A149037

A149037

a(n) is the number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from
{(-1, -1, 0), (-1, 0, 1), (0, 1, 1), (1, -1, 1), (1, 0, -1)}.

a(4) = 35 is illustrated; a(7) = 2018


July

A121551

A121551

a(n) is the number of parts in all the compositions of n into Fibonacci numbers.

a(8) = 457 is illustrated; a(10) = 2018


August

A271996

A271996

a(n) is the crystallogen sequence.

a(7) = 114 is illustrated; a(21) = 2018


September

A229915

A229915

a(n) is the number of espalier polycubes of a given volume in dimension 3.

a(7) = 34 is illustrated; a(20) = 2018


October

A240059

A240059

a(n) is the number of partitions of n such that multiplicity(1) > multiplicity(3).

a(12) = 46 is illustrated; a(27) = 2018


November

A133736

A133736

a(n) is the number of graphs on n unlabeled nodes that have an Eulerian cycle,
i.e., a cycle that goes through every edge in the graph exactly once.

a(6) = 15 is illustrated; a(9) = 2018


December

A005905

A005905

a(n) is the number of points on the surface of a truncated tetrahedron of edge length n (by analogy with triangular numbers).

a(4) = 226 is illustrated; a(12) = 2018


Each of the 13 designs (12 months plus cover) is based on a sequence from the Online Encyclopedia of Integer Sequences® in which the number 2018 occurs. OEIS is a registered trademark of the OEIS Foundation, Inc. This project is neither endorsed by nor affiliated with the OEIS.


source code

source code is available, implemented in Haskell using the Diagrams library:
git clone https://code.mathr.co.uk/oeis-diagrams.git


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