a(n) = number of n-lettered words in the alphabet {1, 2, 3, 4} with as many occurrences of the substring (consecutive subword) [1, 1] as of [1, 2].
A211303
a(n) = number of n-lettered words in the alphabet {1, 2, 3, 4} with as many occurrences of the substring (consecutive subword) [1, 1] as of [1, 2].
Terms
- a(0) =1a(1) =4a(2) =14a(3) =51a(4) =186a(5) =681a(6) =2507a(7) =9272a(8) =34450a(9) =128569a(10) =481865a(11) =1813294a(12) =6849679a(13) =25967722a(14) =98778134a(15) =376923683a(16) =1442500626a(17) =5535489345a(18) =21295353521a(19) =82114239566a(20) =317305643893
External references
- oeis: A211303