1,9

Operation 'time lapse', or 'lapse', L, operates on a solid partition by creating a new one, layer by layer. Layer k is defined by its 3-dimensional-Ferrers plot, equal to the (existence of) elements of the solid partition with value >= k. As if taking a time-lapse picture of the solid partition, filtering out elements less than k, and projecting the resulting structure (filled with ones) to the base plane. Given there are three plane to project into, together with the starting solid partition, that makes four 'isomers'.

Wouter Meeussen, Solid Partitions Mma functions

Solid partition [{{3,1,1,1},{3}},{{2,1}},{{1}},{{1}},{{1}}] lapses (L) into

[{{4,1},{2},{1},{1},{1}},{{1,1},{1}},{{1,1}}], then into

[{{2,1,1,1,1},{2,1},{2}},{{1,1}},{{1}},{{1}}], further into

[{{5,2,1},{2},{1},{1}},{{1,1,1}}], and returns after L^4 to

[{{3,1,1,1},{3}},{{2,1}},{{1}},{{1}},{{1}}]

See link above.

Cf. A000293, A094504, A094508, A096272, A096573, A096574, A096575, A096576, A096578, A096579, A096580, A096581.

Adjacent sequences: A096574 A096575 A096576 this_sequence A096578 A096579 A096580

Sequence in context: A053471 A008614 A036663 this_sequence A137899 A026613 A117199

more,nonn

Wouter Meeussen (wouter.meeussen(AT)pandora.be), Jun 27 2004