Small-number statistic from the enumeration of domino tilings of a 7-pillow of order n.

Terms

a(0) =1a(1) =2a(2) =5a(3) =13a(4) =34a(5) =34a(6) =74a(7) =73a(8) =193a(9) =256a(10) =793a(11) =1049a(12) =2465a(13) =2857a(14) =6577a(15) =8226a(16) =21348a(17) =28872a(18) =74740a(19) =91970a(20) =222217a(21) =268769a(22) =669265a(23) =852305a(24) =2201945a(25) =2805760a(26) =7000777a(27) =8636081a(28) =21311098a(29) =26588770