Number of compositions of n with exactly 4 adjacent equal parts.

Terms

a(0) =1a(1) =0a(2) =2a(3) =9a(4) =14a(5) =33a(6) =92a(7) =189a(8) =411a(9) =926a(10) =2016a(11) =4219a(12) =8935a(13) =18805a(14) =38808a(15) =79928a(16) =163963a(17) =332676a(18) =672036a(19) =1352412a(20) =2705019a(21) =5385960a(22) =10684650a(23) =21105565a(24) =41533076a(25) =81467400a(26) =159263257a(27) =310372453a(28) =603149241a(29) =1168863180