1,6

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 makezs four 'isomers'.

Wouter Meeussen, Solid Partitions Mathematica 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, A096577, A096579, A096580, A096581.

Sequence in context: A018468 A117115 A049196 this_sequence A027754 A092857 A062404

Adjacent sequences: A096575 A096576 A096577 this_sequence A096579 A096580 A096581

more,nonn

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