A322117 Number of non-isomorphic blobs (2-connected weak antichains) of multisets of weight n.

1, 1, 3, 4, 8, 8, 21, 27, 79, 185, 554

Offset

0,3

Links

Table of n, a(n) for n=0..10.

Gus Wiseman, Every Clutter Is a Tree of Blobs, The Mathematica Journal, Vol. 19, 2017.

Example

Non-isomorphic representatives of the a(1) = 1 through a(6) = 21 blobs:
  (1)  (11)    (111)      (1111)        (11111)          (111111)
       (12)    (122)      (1122)        (11222)          (111222)
       (1)(1)  (123)      (1222)        (12222)          (112222)
               (1)(1)(1)  (1233)        (12233)          (112233)
                          (1234)        (12333)          (122222)
                          (11)(11)      (12344)          (122333)
                          (12)(12)      (12345)          (123333)
                          (1)(1)(1)(1)  (1)(1)(1)(1)(1)  (123344)
                                                         (123444)
                                                         (123455)
                                                         (123456)
                                                         (111)(111)
                                                         (112)(122)
                                                         (122)(122)
                                                         (123)(123)
                                                         (123)(233)
                                                         (134)(234)
                                                         (11)(11)(11)
                                                         (12)(12)(12)
                                                         (12)(13)(23)
                                                         (1)(1)(1)(1)(1)(1)

Crossrefs

Cf. A002218, A007718, A013922, A275307, A286520, A293994, A304118, A304887, A319719, A319721, A322110, A322118.

Sequence in context: A047968 A358835 A358833 * A181778 A245026 A125219

Adjacent sequences: A322114 A322115 A322116 * A322118 A322119 A322120

Keyword

nonn,more

Author

Gus Wiseman, Nov 26 2018

Status

approved