Number of chains in the power set lattice, or the number of fuzzy subsets of an (n+4)-element set X_(n+4) with specification n elements of one kind, 3 elements of another and 1 of yet another kind.
A107954
Number of chains in the power set lattice, or the number of fuzzy subsets of an (n+4)-element set X_(n+4) with specification n elements of one kind, 3 elements of another and 1 of yet another kind.
Terms
- a(0) =79a(1) =527a(2) =2415a(3) =9263a(4) =31871a(5) =101759a(6) =307455a(7) =890111a(8) =2490367a(9) =6774783a(10) =18001919a(11) =46886911a(12) =120029183a(13) =302678015a(14) =753205247a(15) =1852375039a(16) =4507828223a(17) =10866393087a(18) =25970081791a(19) =61583917055a(20) =144997089279a(21) =339159810047
External references
- oeis: A107954