oeis.haskell

Collection of OEIS Number Sequences in Haskell

Samples

Hypercube Colorings

• A333333 - Irregular triangle: T(n,k) gives the number of k-polysticks on edges of the n-cube up to isometries of the n-cube, with 0 <= k <= A001787(n)

module HypercubeColorings.A333333 (a333333) where
import Helpers.HypercubeColorings (countPolyforms)

a333333_row :: Int -> [Int]
a333333_row n = map (a333333T n) [0..n*2^(n-1)]

a333333T :: Int -> Int -> Int
a333333T n = countPolyforms n 1

a333333_list :: [Int]
a333333_list = concatMap a333333_row [1..]

a333333 :: Int -> Int
a333333 n = a333333_list !! (n - 1)

Tilings

• A303930 - Count leaf-free subgraphs of the 2 X n grid up to horizontal and vertical flipping

module Tiling.A303930 where

a303930 :: Int -> Integer
a303930 n = a303930_list !! (n - 1)

-- A303930
a303930_list :: [Integer]
a303930_list = map (`div` 4) sumOfOrbits where
  sumOfOrbits = foldr (zipWith (+)) allCount [rotationalCount, horizontalCount, verticalCount]

-- A093129
allCount :: [Integer]
allCount = 1 : 2 : recurse 1 2 where
  recurse a b = nextTerm : recurse b nextTerm where
    nextTerm = 5 * (b - a)

-- A001519
verticalCount :: [Integer]
verticalCount = 1 : 2 : recurse 1 2 where
  recurse a b = nextTerm : recurse b nextTerm where
    nextTerm = 3 * b - a

horizontalCount :: [Integer]
horizontalCount = 1 : 2 : 3 : 7 : recurse 1 2 3 7 where
  recurse a b c d = nextTerm : recurse b c d nextTerm where
    nextTerm = 5 * (c - a)

rotationalCount :: [Integer]
rotationalCount = 1 : 2 : 3 : 5 : recurse 1 2 3 5 where
  recurse a b c d = nextTerm : recurse b c d nextTerm where
    nextTerm = 5 * (c - a)

Contents

• Anagram
• Binary
• Braxton
• BrickStacking
• Chess
• Coins
• CoinsInARow
• ConcavePolygon
• ConvexPolygon
• CostasLikeArrays
• Delahaye
• DistinctMidpoints
• DoubleOrIncrement
• EKG
• External
• Graham
• GridPolytopes
• HelperSequences
• Helpers
• HeronianTriangles
• HypercubeColorings
• IntegerTriangles
• KthDifferences
• Minecraft
• Miscellaneous
• NestedRoots
• Nonpalindromes
• Palindromes
• Permutations
• PolygonSizes
• Polynomial
• Poset
• PowerDivisibility
• ProjectEuler
• RemainderGame
• RichardGuy
• SqrtMultiples
• Staircase
• StoneTransfer
• SubprimeFib
• Subsets
• TableDifferences
• Tables
• Tiling
• ToiletPaper
• Walk
• XorTriangle

Sources

The sequence definitons are from The Online Encyclopedia of Integer Sequences - visit OEIS

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