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A214521
List of words over {1,4} with equal numbers of 1's and 4's.
5
14, 41, 1144, 1414, 1441, 4114, 4141, 4411, 111444, 114144, 114414, 114441, 141144, 141414, 141441, 144114, 144141, 144411, 411144, 411414, 411441, 414114, 414141, 414411, 441114, 441141, 441411, 444111, 11114444, 11141444
OFFSET
1,1
COMMENTS
This is to 4 as A214488 is to 3, and as A214218 is to 2. The subsequence of primes (when interpreted as decimal integers) is A087512.
MATHEMATICA
Sort[FromDigits/@Flatten[Table[Permutations[PadRight[{}, 2n, {1, 4}]], {n, 4}], 1]] (* Harvey P. Dale, Aug 30 2016 *)
CROSSREFS
Sequence in context: A044007 A366480 A199710 * A064512 A118237 A326624
KEYWORD
nonn,base
AUTHOR
Jonathan Vos Post, Jul 19 2012
STATUS
approved